The Trump administration said on Monday it was vastly expanding the scope of a policy blocking U.S. assistance to foreign groups that perform or provide information about abortions, a move critics say will hinder women's access to critical care.

The new policy means that US$8.8 billion in U.S. assistance to an array of programs fighting HIV/AIDS, malaria and maternal and child health will be subject to the so-called Mexico City policy.

The policy, introduced in 1984, holds that no U.S. government funding for family planning services can be given to foreign clinics or groups that offer abortion services or discuss abortion, even if the funds for those activities come from non-U.S. government sources.

The policy previously applied to a much narrower stream of about US$600 million in U.S. government funds.

Since it was unveiled, the Mexico City rule has been routinely rescinded under Democratic administrations and reinstated under Republican ones and is used by presidents to signal where they stand on abortion rights.

Critics of the policy call it the "global gag rule," and say it hurts vulnerable women worldwide who depend on aid groups for their healthcare. Even when the Mexico City policy is not in place, federal law prevents the use of U.S. funding for abortions abroad.