The State Department is stepping up its advice to Americans in India and Pakistan to leave the two countries as tensions between the two nuclear-armed states remain high.

New travel warnings due to be issued later Tuesday will strongly urge Americans to depart, a U.S. official told The Associated Press. This is a tougher approach than past statements urging Americans to consider leavin the same last week.

Secretary of State Colin Powell is sending his deputy to South Asia and pledging "a full-court diplomatic press" to avert war between India and Pakistan.

Curbing Pakistani Islamic extremists from infiltrating disputed Kashmir and attacking Indian soldiers is the first priority of Deputy Secretary of State Richard Armitage and Defense Secretary Donald H. Rumsfeld, who are traveling separately to India and Pakistan in coming days.

The next step would be to urge India to reciprocate, presumably by withdrawing hundreds of thousands of troops from the frontier with Pakistan, Powell said Monday.

From there, Powell hopes to move India and Pakistan into face-to-face negotiations over the future of the Himalayan territory they both claim.

Armitage, who leaves Tuesday, is due in Pakistan on Thursday and in India on Friday. Rumsfeld is expected in the area this weekend.

Powell, at a news conference in Barbados where he attended an Organization of American States foreign ministers meeting, said he was heartened that both India and Pakistan have played down the possible use of nuclear weapons.

"It would be absolutely horrible in the year 2002 for any nation to use nuclear weapons in a situation such as this," Powell said.

India and Pakistan have fought two wars over Kashmir, which is divided between them by a 1972 negotiated line of control that generally followed a cease-fire line established in 1949.

The last three U.S. administrations have had to become deeply involved in the Kashmir dispute to avert a feared nuclear war, said Lee Feinstein, who was deputy director for policy planning at the State Department during the Clinton administration.

For the first time, the United States has good relations with India and Pakistan simultaneously, and India must know U.S. diplomacy is the only chance of reining in Pakistan, Feinstein said in an interview.

"The Americans and Russians were very lucky over the 50 years that their conflicts didn't go nuclear," Feinstein said in an interview.

"The circumstances with India and Pakistan are much more dire," he said. "They share a border, they have had hot conflicts, and they don't have the same kind of command and control systems the Americans and Russian built over several decades that could help prevent war by miscalculation or accident."

Robert Oakley, U.S. ambassador to Pakistan from 1988 to 1991, enthusiastically endorsed the Bush administration's strategy, saying it would lead to decreased tension.

"The question is then whether we can work out a long-term solution with a permanent decrease of tensions, stabilizing the region and conducting the war on terrorism," Oakley said in an interview.

"You can't ever be sure, but my guess is tensions will be reduced," he said. "It's prudent to evacuate American dependents and to tell both India and Pakistan, `If you misbehave, it's going to be very, very costly in terms of long-term relations with the United States."'

Lester Paldy, an arms control specialist and a professor at the State University of New York at Stony Brook, said India and Pakistan were unlikely to start shooting with high-level U.S. officials in the area and thousands of Americans in the two countries.

But, he said, "if people make miscalculations, that's the real danger."

Another, Paldy said, is that India and Pakistan may have spread their nuclear weapons. That, he said, means commanders at various sites may have authority to launch nuclear weapons if there is an attack.

All nonessential U.S. officials were ordered to leave Pakistan in March. The State Department urged a similar exodus from India last week, and most will have left by the end of this week, said Philip Reeker, deputy State Department spokesman.