The State Department on Friday urged about 60,000 Americans — including all non-essential American diplomats — to voluntarily leave India as the South Asian nation inches ever closer to war with nuclear neighbor Pakistan.

"Tensions have risen to serious levels" and conflict between India and Pakistan cannot be ruled out, the State Department said.

"Conditions along India's border with Pakistan and in the state of Jammu and Kashmir have deteriorated," the State Department said in its travel warning.

The warning cited artillery exchanges between Indian and Pakistani troops and said terrorist groups linked to the Al Qaeda network have attacked and killed civilians.

White House spokesman Scott McLellan said President Bush was informed of the recall Friday.

"Anytime you have tension between two countries that possess nuclear weapons, it is a serious situation and that is all the more reason why high-level diplomacy is ongoing with India and Pakistan," McClellan said.

Dependents of nonessential U.S. personnel in the embassy in New Delhi and U.S. consulates in Calcutta, Mumbai and Chennai also were encouraged to depart.  The State Department said it will help make arrangements but will not pay for Americans to find their way home.

It was not clear how many Americans would take the State Department's advice.

"Departure is voluntary, so people have to make their decisions on their own, and we can't say exactly at this point how many will desire to leave, how many will — when they'll start to leave," State Department spokesman Richard Boucher said Friday, adding that the differences between ordered and voluntary departures are "the level of tensions, the kind of transportation available, the likelihood of future transportation, the environment for those who stay."

In Pakistan, all nonessential U.S. Embassy staff and dependents were ordered home after the March 17 bombing of a Christian church in Islamabad that killed four people, including two Americans. A travel warning that already was in effect was reissued, urging Americans to postpone trips to Pakistan, but there have been no warnings for them to leave voluntarily.

Dozens of embassy staff remain. The embassy in Islamabad is open, as are consulates in Karachi, Peshawar and Lahore, although they are heavily fortified.

On Friday, Britain also advised departure from India of all its non-essential diplomatic personnel, which number about 350 government staff and dependents. British citizens were also warned to leave.

India regularly warns the State Department of preparations for war with Pakistan because of the influx of Islamic extremists into the Indian side of disputed Kashmir, said a senior U.S. official, speaking on condition of anonymity.

While India has not indicated a timetable, the administration takes the warnings seriously.

On Thursday, President Bush dispatched top American officials to the region.

"We are making it very clear to both Pakistan and India that war will not serve their interests," he said.

Powell will send his deputy, Richard Armitage, to India and Pakistan for talks next Thursday and Friday, with Defense Secretary Donald H. Rumsfeld to arrive shortly afterward, State Department spokesman Richard Boucher said.

"We have no desire to make ourselves the mediator," Boucher said. He said any solution to the dispute over Kashmir depends on dialogue and taking into account the wishes of the people of the territory.

Bush also demanded that Pakistani President Pervez Musharraf "live up to his word" and crack down on Islamic extremists' cross-border attacks in Kashmir. Pakistan is a major ally in the U.S. war against the Al Qaeda terror network.

While the State Department said it still had no assessment whether Musharraf was making good on his promise last winter to deny Pakistani territory to terrorists, Bush took the initiative as India and Pakistan teetered on the brink.

Locked in a dispute over the Kashmir border district, and with 1 million troops in a standoff at their frontier, India and Pakistan continued to alarm the world with their troop movements and their rhetoric, their nuclear armaments looming always in the background.

Under rules guiding the 1947 partition of British India, overwhelmingly Muslim Kashmir went to Indian control because its Hindu maharajah wanted it. The first India-Pakistan war over Kashmir resulted in a cease-fire line, which became a "line of control" under a 1972 agreement, with Hindu India controlling three-fifths of the fertile, predominantly Muslim Himalayan region.

The United Nations has been on record since the late 1940s that Kashmir's political status should be decided by its people, including a series of Security Council resolutions demanding plebiscites. Pakistan's position is that the resolutions should be implemented.

India has rejected the resolutions, for reasons including that no test of the people's will was required in other British India principalities divided because of their leaders' wishes and that Pakistan has not withdrawn from territory it controls.

The Bush administration has focused its diplomacy on trying to pry the two armies apart.

Powell said Thursday "there is nothing active" for the two sides to discuss in the way of a settlement. And, he said on PBS' NewsHour With Jim Lehrer, he did not think there was a role for the United States or another outside mediator at this point.

Asked if nuclear weapons would be used by India or Pakistan if conflict came, Powell said: "I can't answer that question, but I can say this: In my conversations with both sides, especially with the Pakistani side, I have made it clear that this really can't be in anyone's mind."

"We are making it very clear to both Pakistan and India that war will not serve their interests," Bush said after a Cabinet meeting. "We are part of an international coalition applying pressure to both parties."

In particular, he said, Musharraf must keep his promise to stem attacks across Kashmir's internationally established dividing line.

"He must stop the incursions across the line of control. He must do so. He said he would do so," the president said. "We and others are making it clear to him that he must live up to his word."

Despite Pakistan's assertion that it already has begun moving troops away from the Afghan-Pakistan border because of the tensions with India, Rumsfeld said U.S. officials had as yet seen no signs of a redeployment.

Pentagon officials speaking on condition of anonymity said Pakistan had begun moving equipment and weapons away from the Afghan border area but, as of Thursday, had moved no troops.

Even if Pakistani troops are moved, Bush pledged to continue efforts to track down members of the Al Qaeda terror network in Pakistan.

The Associated Press contributed to this report.