Washington will also use this time to look for alternative partners outside the WHO to continue to carry out "important work" such as on vaccines, to ensure there is no disruption to U.S. aid efforts, said John Barsa, who heads USAID, the key U.S. government agency that administers foreign aid.

U.S. funding to the World Health Organization will be halted, pending a review.

Speaking at press conference on Tuesday, Trump first said the U.S. will put a "very powerful hold" on money sent to the WHO, but later backtracked and said he was going to "look at" doing it.