“No new funds will be charged for new awards or renewals of existing awards until each proposed new award or renewal has been reviewed and approved,” the memo to employees said.
It added that US officials would “immediately issue cease-and-desist orders in accordance with the terms of the applicable award until such time as the Secretary determines upon review.”
It also orders a wide-ranging review of all foreign aid within 85 days to make sure the aid meets President Trump’s foreign policy goals.
Secretary of State Marco Rubio, the US’s top diplomat, has previously said that all US spending abroad should only happen if it makes America “stronger”, “safer” or “more prosperous”.
One former senior State Department official told the BBC the announcement meant a “potentially large” impact on US-funded foreign aid programmes.
“One can imagine, for example, humanitarian demining programs around the world, which will suddenly be told to stop working. It’s a pretty big deal,” said Josh Paul, who oversaw congressional relations for the State Department’s arms deals through the end of 2023.
Dave Harden, former director of the US Agency for International Aid’s (USAID) mission in the Middle East, told the BBC the move was “very significant”, saying it could lead to US-funded humanitarian and development programs across the world, will be immediately suspended. while the review is underway.
He said it could affect a wide range of important development projects, including water, sanitation and housing.
“The staff of the implementing partner or (non-governmental organization) could be paid, but the actual aid, I think, should be stopped,” Mr Harden said.
“I went through (suspension of aid) many times when I was mission director in the West Bank and Gaza, but it was especially for this account. It’s global… it’s very broad,” he said.
“This not only suspends aid, but also puts a ‘stop work’ order on existing contracts that are already funded and in progress. It is very broad,” he added.
The AFP news agency reported that the funding freeze could also affect Ukraine, which received billions of dollars in arms under Trump’s predecessor, Joe Biden.
Rubio’s memo, justifying the freeze, said it was impossible for the new administration to assess whether “existing foreign aid commitments are duplicative or effective and consistent with President Trump’s foreign policy.”
According to the memo, Rubio issued a waiver for emergency food assistance.
It comes amid a surge in humanitarian aid to the Gaza Strip following the start of a cease-fire between Israel and Hamas and several other hunger crises around the world, including Sudan.
The memo also said Rubio has so far approved a waiver of “foreign military funding for Israel and Egypt and administrative costs, including salaries, required to administer foreign military funding.”
The State Department has been contacted for comment.