Rough times are ahead for the United Nations (UN) with the election of Donald Trump to a second term. Although we do not yet know the details of the incoming administration’s UN policy agenda, the experience of his first term (2017–2021) provides a good starting point. A confrontational stance toward the UN and multilateralism is to be expected, particularly given the nomination of Marco Rubio as Secretary of State and Elise Stefanik as US Ambassador to the UN. In addition, documents such as Project 2025 and the America First Agenda already provide glimpses into what to expect over the next four years. Although Trump has sought to distance himself from Project 2025, the chapters relevant to the UN were drafted by individuals in Trump’s orbit who held senior positions in the Department of State and US Agency for International Development (USAID) during Trump’s first administration. Personnel is policy, as the mantra goes, and therefore the priorities and positions of the individuals in senior positions are likely to drive the positions of the United States in a second Trump administration.

Much has already been written on the likely contours of foreign policy over the next four years, so this article will focus on the potential impacts on the operational functioning of the UN.

Funding Challenges

The UN has faced financial challenges since the earliest days of the organization. Its liquidity challenges, however, have been particularly acute in recent years due in large part to practices of the United States, the top financial contributor to the UN. The core activities of the UN within its program (regular) budget as well as its peacekeeping operations are funded through assessed contributions, which are the responsibility of all UN member states based on scales of assessments negotiated by the General Assembly every three years. Other activities, including the bulk of development and humanitarian assistance work at the country level, are funded through voluntary contributions.

Regular budget

Since 2001, the US has been responsible for 22 percent of the UN’s regular budget, which operates on the basis of the calendar year. Although the financial regulations adopted by the General Assembly specify that contributions are payable within 30 days, the United States has, since the 1980s, generally paid toward the end of the calendar year (i.e., in the beginning of the next US fiscal year). This practice of late payment creates liquidity challenges that affect the ability of the UN to execute the program budget adopted each year by consensus. It also creates a catch-22 situation in which US funding practices drive many of the shortcomings in program delivery that feed narratives of UN inefficiency.

The United States also engages in various forms of withholding driven by the policy preferences of members of the US Congress. For example, legislation from the 1980s requires the United States to deduct amounts from its contributions to the regular UN budget corresponding to activities related to Palestine. Legislation from the 1990s also prohibits the United States from providing any funds (assessed or voluntary) to the UN or any specialized agency that grants membership to Palestine. After the General Assembly adopted a resolution in May 2024 granting Palestine additional rights and privileges of participation in the UN, Republicans in both houses of Congress pushed to extend this prohibition to any organization providing Palestine “any status, rights, or privileges beyond observer status.” No action was taken on these proposals during the current session of Congress, but this could change next year when Republicans control both houses. If the US suspends its payments to the UN, it could lose its vote in the General Assembly, though its ability to participate and vote in the other main organs, including the Security Council, would remain unaffected.¹

Peacekeeping budgets

Since the 1990s, Congress has also levied a “legislative cap” preventing the United States from paying over 25 percent of the expenses of peacekeeping operations. Because the United States assessment for peacekeeping operations has always exceeded 25 percent,² this cap has led the US to steadily accumulate peacekeeping arrears over time. As of September 30, 2024, US arrears for peacekeeping amounted to $883 million, or 15.8 percent of the total approved peacekeeping budget for the current financial period. Although the US assessment for peacekeeping is expected to decrease as part of the ongoing negotiations in the Fifth Committee over the scales of assessments for 2025–2027, the rate will still exceed 25 percent. The accumulation of peacekeeping arrears is therefore expected to continue, though at a slower rate. This will exacerbate cash management challenges for the UN, especially as the overall peacekeeping budget is decreasing.

It must be emphasized that the United States is not solely responsible for the financial challenges facing the UN, even if its practices have an outsize effect. Another contributing factor has been the recent trend of China, the second largest contributor, also paying late (though without withholdings, unlike the United States). This practice is likely to persist in the coming years, which will further exacerbate liquidity challenges in the UN, especially as China’s share of both the regular and peacekeeping budgets continues to grow on account of its growing share of the global economy.

Beyond questions of liquidity, a second Trump administration also will likely stall several initiatives related to the use of peacekeeping financing. These include the push by the Biden administration to “transform” the Multinational Security Support mission in Haiti into a UN peacekeeping operation to address its persistent funding shortfall as well as the efforts underway to operationalize Security Council Resolution 2719 on financing of African Union–led peace support operations. Both initiatives have a history extending back to the first Trump administration, which pushed for the drawdown and closure of UN peacekeeping operations in Haiti and used the threat of a veto to scupper an earlier attempt at a Security Council resolution on the financing of AU peace operations.

Voluntary contributions

A second Trump administration would also likely significantly reduce US voluntary contributions to the UN. During the first Trump administration, the White House pushed to eliminate the International Organizations and Programs account in the federal budget, from which direct voluntary contributions to UN system organizations are paid, though this push was blocked by Congress. During the Biden administration, Republicans in the House have also pushed to eliminate this account, which is a portent of what is likely to come next year when Republicans control the White House and both houses of Congress. UN organizations can also receive voluntary contributions through other thematic accounts in the budget, such as those for global health programs, development assistance, and international disaster assistance. UN entities (including funds and programs) whose activities are at odds with Trump administration policies (e.g., on abortion, climate, and the environment) are likely to experience a halt in funding. Project 2025 also makes it clear that organizations that rely disproportionately on US funding should expect significant reductions, though it is not clear what criteria would be used to determine overreliance.

Personnel

Personnel is another area where the UN can expect a shakeup under a second Trump administration. The UN is gearing up for the selection of the next secretary-general in 2026. Article 97 of the UN Charter specifies that the secretary-general “shall be appointed by the General Assembly upon the recommendation of the Security Council.” In practice, this means that the United States and the other permanent members of the Security Council can exercise the veto over candidates. As such, the growing divisions in the Security Council and the Trump administration’s skepticism toward multilateralism make the election of a dynamic secretary-general with a bold vision for the UN highly unlikely.

Moreover, US nationals hold several key policy positions at the UN as part of a tacit system of member-state dominance over senior leadership positions that primarily benefits the five permanent members of the Security Council. Although most senior officials in the UN are appointed by the secretary-general, the US government has exercised considerable influence over the selection process for many of the positions traditionally held by US nationals, such as the executive directors of UNICEF and the World Food Programme (WFP), the under-secretary-general for political and peacebuilding affairs, and the deputy high commissioner for refugees. In recent years, most of the incumbents in these positions have been former US government officials or politicians, and individuals pushed by the second Trump administration for these positions can therefore be expected to drive agendas aligned with those of the administration.

Conclusion

The UN liquidity situation is unlikely to improve under a second Trump administration. More broadly, the United States under Trump is likely to be critical toward the UN, though this is not necessarily a bad thing. For example, the Trump administration is likely to push for reforms to increase UN effectiveness. Although this generally translates to a push for cost-cutting, the next secretary-general could capitalize on this emphasis on reform to drive a meaningful reform agenda, particularly in the “honeymoon” period at the start of their term.

Even if the United States under a second Trump administration were to find itself at complete loggerheads with the UN Secretariat or the bulk of the membership, the United States is unlikely to withdraw from the UN. This is for practical reasons; to withdraw from the UN would deprive the United States of a significant source of global influence, including through its status as a permanent member of the Security Council with the ability to wield the veto.³ As outlined above, the United States has more means by which to exert its influence if it remains a member state. Ultimately, the United States needs the UN as much as the UN needs the United States.

The next four years will not be an easy time at the UN, but this is not the first time the UN has had to navigate periods of financial difficulty and geopolitical division. The UN will likely survive a second Trump administration, but the experience will leave it a significantly changed organization. In previous crises, the Secretariat and member states have demonstrated significant creativity that has helped the UN maintain its relevance despite the challenges, including through greater use of the General Assembly. Whether the organization will emerge this time as a diminished institution or whether it can rise to the occasion by refocusing and reinventing itself will depend largely on the quality of its leadership, the dedication of its staff, and the creativity of its (other) member states.

Eugene Chen is a senior fellow at the NYU Center on International Cooperation.

^{[1] Article 19 of the UN Charter indicates that member states whose arrears exceed their cumulative assessment over the previous two years lose their voting privileges unless they are granted a waiver by the General Assembly.}

^{[2] The United States pays a higher share of peacekeeping budgets than for the regular budget because the five permanent members pay an additional “premium” for peacekeeping taking into account their special responsibilities for the maintenance of peace and security.}

^{[3] It is true that Trump withdrew the United States from UNESCO during his first term, but at that point the United States had already lost its vote in the UNESCO General Conference on account of its arrears. The withdrawal was therefore mostly symbolic.}