WASHINGTON (AP) _ About 900 U.S. troops will deliver emergency supplies and help rescue flood victims in Mozambique, Clinton administration officials said Wednesday.

Two contingents of troops, based mostly in Europe, were heading immediately for the African country, White House National Security Council spokesman David Leavy said.

The United States is sending six C-130 transport planes to ferry aid and supplies and six MH-53 helicopters to help lift people from mud and treetops.

The United states already has pledged $12.8 million in emergency relief and military assistance. President Clinton said one U.S. military plane delivered relief supplies to Mozambique on Wednesday, and a second was to arrive shortly in South Africa.

``But we can do more to address the needs of the nearly 1 million people who have been displaced,'' Clinton said in announcing the new assistance.

The government of Mozambique estimates thousands are trapped by high waters.

International aid agencies have appealed for more helicopters and boats after last week's disaster swelled beyond the expectations of relief agencies and donors.

An appeal last week raised nearly $2.8 million _ enough money to lease seven helicopters and five airplanes _ but those resources were not enough, a United Nations food agency said Wednesday.

The U.S. aid already committed includes $4 million for helicopter search and rescue operations, and a water rescue team from the Miami area.