The US State Department has frozen nearly all foreign assistance worldwide, effective immediately, days after President Donald Trump issued a sweeping executive order Monday to put a hold on such aid for 90 days.

Secretary of State Marco Rubio sent a cable, seen by CNN, to all US diplomatic posts on Friday outlining the move, which threatens billions of dollars of funding from the State Department and the US Agency for International Development (USAID) for programs worldwide.

Foreign assistance has been the target of ire from Republicans in Congress and Trump administration officials, but the funding accounts for very little of the overall US budget. The scope of the executive order and subsequent cable has left humanitarian and State Department officials reeling.

The cable calls for immediate “stop work” orders on existing foreign assistance and pauses new aid. It is sweeping in its scope. Essentially all foreign assistance appears to have been targeted unless specifically exempted. That means lifesaving global health aid, development assistance, military aid, and even clean water distribution could all be affected.

The cable provides a waiver only for emergency food assistance and foreign military financing for Israel and Egypt. The cable does not specifically mention any other countries that receive foreign military financing, like Ukraine or Taiwan, as being exempt from the freeze.

In the coming month, the cable said, the administration will develop standards for a review of whether the assistance is “aligned with President Trump’s foreign policy agenda.”

“Decisions whether to continue, modify, or terminate programs will be made following this review,” the cable states, noting that such a review should be completed within 85 days.

In a public statement on Wednesday, Rubio said that “every dollar we spend, every program we fund, and every policy we pursue must be justified with the answer to three simple questions: Does it make America safer? Does it make America stronger? Does it make America more prosperous?”

The impact of the freeze on assistance will be immense because the US is consistently the world’s largest humanitarian donor.

“It’s a global freak out at the moment,” a humanitarian official said Saturday.

InterAction, an alliance of international nongovernmental organizations, said in a statement Saturday that the freeze “interrupts critical life-saving work including clean water to infants, basic education for kids, ending the trafficking of girls, and providing medications to children and others suffering from disease. It stops assistance in countries critical to U.S. interests, including Taiwan, Syria, and Pakistan.”

“The recent stop-work cable from the State Department suspends programs that support America’s global leadership and creates dangerous vacuums that China and our adversaries will quickly fill,” the statement said.

One humanitarian official said the pause is incredibly disruptive and said the specifics of the cable are “as bad as can be.”

Another official told CNN that while they expected there to be cuts or changes to assistance to specific areas, they were not expecting such a sweeping and immediate pause. They said that the humanitarian needs worldwide are acute and a freeze in assistance from the US could be detrimental.

In his executive order, Trump claimed that the US “foreign aid industry and bureaucracy are not aligned with American interests and in many cases antithetical to American values.”

However, one of the officials noted that assistance programs, such as those related to global health, which are targeted by the freeze, are in the US’ interest and had enjoyed bipartisan support.

“Making sure there are not pandemics is in our interest. Global stability is in our interest,” they said.

Democratic Reps. Gregory Meeks of New York and Lois Frankel of Florida said in a Friday letter to Rubio that programs that appear affected by the freeze such as the President’s Emergency Plan for AIDS Relief (PEPFAR) and the President’s Malaria Initiative (PMI) “depend on an uninterrupted supply of medicines.” PEPFAR and PMI were launched by Republican President George W. Bush and have long enjoyed bipartisan support.

Meeks serves as the top Democratic on the House Foreign Affairs Committee and Frankel is a member of the State, Foreign Operations, and Related Programs Appropriations Subcommittee, meaning they both have oversight over State Department and USAID funding.

They added that people around the world — such as in conflict-ridden Gaza, Sudan, Haiti and Ukraine — rely on the continued flow of aid from the United States.

“Congress has appropriated and cleared these funds for use, and it is our constitutional duty to make sure these funds are spent as directed,” the letter read. “These funds respond directly to your stated challenge of carrying out a foreign policy that makes the United States stronger, safer, and more prosperous.”

The International AIDS Society warned on Saturday that halting PEPFAR would place millions of lives in jeopardy. IAS President Beatriz Grinsztejn said in a statement, “This is a matter of life or death. PEPFAR provides lifesaving antiretrovirals for more than 20 million people — and stopping its funding essentially stops their HIV treatment. If that happens, people are going to die and HIV will resurge.”