The order pausing funding follows an executive order directing the State Department to implement an “America First foreign policy,” although the specifics of that policy are not defined.

Trump is directing department and agency heads with responsibility for U.S. foreign development assistance programs to immediately pause new obligations and disbursements of development assistance funds to foreign countries; non-governmental organizations, international organizations or contractors.

The president calls for a review of these programs for “programmatic efficiency” and to determine whether they are consistent with U.S. foreign policy. The Office of Management and Budget will “enforce this pause,” the executive order states.

The executive order includes a waiver for the secretary of State to waive the rules for “specific programs.”

It also allows funding to resume earlier than 90 days if a review is conducted and the secretary of State or his designee, in consultation with director of OMB, decide to continue the program in the same or in a modified form.

The measure encroaches on the legislative branch’s control over spending, which could create friction in Congress.

Secretary of State Marco Rubio, who was confirmed unanimously by the Senate on Monday, affirmed Congress’s “power of the purse” in appropriations.

“The power of the purse still resides with the Congress. Now maybe if confirmed, moving towards the executive branch, I’ll forget that lesson a little bit,” he joked during his confirmation hearing, “I hope not. But ultimately I still recognize and understand that the power of the purse is with Congress and it’s an incredibly important power.”

At the same time, there have been some critics in Congress of how some foreign aid is distributed.

House Foreign Affairs Committee Chairman Brian Mast (R-Fl.), for example, has put U.S. assistance in the crosshairs. He criticized U.S. funding for NGO programs in Ecuador that have drag performers read stories, and the discovery of funding for an organization promoting atheism in Nepal.

Republicans last week were outraged to learn that nurses in Mozambique, receiving funding through the anti-Aids program in Africa PEPFAR, had performed an estimated 21 abortions, in violation of federal law surrounding the program.

The U.S. has historically been the largest funder of the Geneva-based organization, which is a branch of the United Nations responsible for combating global public health emergencies.

Public health experts fear the move will weaken the organization as well as global health security.

Trump has previously tried to remove the U.S. from the organization, issuing a notice of withdrawal in 2020. He criticized the organization for its handling of the COVID-19 pandemic, calling it very “China centric” and threatened to withhold U.S. funding even while his administration was scrutinized for downplaying the virus’s threat early in the pandemic.

Former President Joe Biden quickly rejoined the organization when he entered the White House in 2021, before the end of the one-year waiting period of withdrawal had completed. He also restored U.S. funding to the organization.

In his Monday executive order, Trump again criticizes the WHO for its “mishandling” of the COVID-19 pandemic for “unfairly” asking for “onerous” payments from the U.S.

About a fifth of the WHO’s budget in 2023 — or roughly $1.28 billion — came from the United States.

Those funds went toward identifying and responding to health emergencies and stopping disease threats from spreading across borders, according to the WHO’s website.

The U.S. withdrawal from the WHO would mean the country’s health agencies would lose access to the organization’s resources, such as global data releases.

“The US withdrawing from the WHO will severely constrain the ability of the US to have situational awareness of infectious disease emergencies occurring all over the world all the time (including now),” stated Amesh Adalja, a senior scholar at the Johns Hopkins Center for Health Security who specializes in emerging infectious diseases and pandemic preparedness.

“The very real reforms that need to occur at the WHO such as putting pressure on China regarding information on the early days of COVID-19 and allowing Taiwan to be part of the organization are less likely to occur without the US as a member.”

Trump has also signed an executive order officially beginning the withdrawal of the U.S. from the Paris Climate Agreement.

The newly inaugurated president signed the order at an inauguration event at Washington’s Capital One arena, following up on a memo earlier in the day confirming it would be among his first executive actions. Trump withdrew the U.S. from the agreement in his first term as well, finalizing the process in 2020 only for former President Biden to reenter the agreement in his first year in office.

The multiyear process, when complete, will make the U.S. one of only a handful of countries that are not party to the agreement, along with Iran, Libya and Yemen. The nonbinding agreement includes a commitment among members to reduce greenhouse gas emissions, the primary cause of climate change, to avert warming beyond 1.5 degrees Celsius above the preindustrial average.

Withdrawal from the agreement was anticipated to be among Trump’s first actions in office, which are expected to focus in large part on energy and environmental policy. Trump has vowed to undo a number of Biden climate moves, including restrictions on offshore drilling along the East and West coasts. The new president has also said he will take action to block new approvals for offshore wind projects and undo a Biden administration freeze on new exports of liquefied natural gas.

Trump’s initial actions are largely the inverse of Biden’s first days as president, which saw him reenter the Paris agreement, block the approval of the Keystone XL Pipeline and announce a temporary pause on new oil and gas leases on public lands.