Tensions between India and Pakistan have created a perilous situation, and the United States will try to coax both parties to calm down, Secretary of State Colin Powell said Friday.

"It is very dangerous," Powell said in Moscow during a walking tour of the Cathedral Square, which is graced by the Kremlin. "I hope both sides realize they are at a very critical point, and we will get them to step back."

Powell, accompanying President Bush on a six-day European trip, said he had spoken to Pakistani President Gen. Pervez Musharraf on Thursday. He then called Indian Foreign Minister Jaswant Singh on Friday from Moscow in another effort to lessen tensions.

"There is concern worldwide," Greek Foreign Minister George Papandreou said after calling on Deputy Secretary of State Richard Armitage.

Pakistan notified India on Friday that it intends to test short- and medium-range missiles from Saturday through Monday. In response, White House press secretary Ari Fleischer said the U.S. "reminds both India and Pakistan that they have to ease tensions" and work maintain peace.

Taking a hard line against Islamic militants streaming into Kashmir from Pakistan, the Bush administration is strengthening U.S. military cooperation with India.

The United States and India agreed to accelerate the pace of defense cooperation and planned to conduct more joint military exercises, according to a statement issued after three days of talks with Indian defense officials at the Pentagon. The statement condemned "the recent upsurge in terrorist attacks against India."

The statement did not refer directly to Pakistan, which India accuses of permitting Islamic militants to cross into Kashmir, where they attack and kill Indian soldiers.

The State Department said it understood India's frustration and anger over continuing terror attacks.

Still, "rather than being the solution, military action in this crisis would create even greater problems," Philip Reeker, a department spokesman, said as the administration focused its diplomacy on trying to avert a war over Kashmir.

Secretary of Defense Donald H. Rumsfeld said Friday there's no question that India and Pakistan "have the capability for waging a nuclear war." Asked how catastrophic such a war would be, Rumsfeld replied, "I have a lot of information and I' m not inclined to get into it... It would be bad. It would not be pretty."

Rumsfeld said the U.S. has not changed or updated its contingency or evacuation plans for American embassies in the two countries, despite the increasing tensions.

On the diplomatic front, Powell spoke to Musharraf twice by telephone from Germany. He also conferred three times by telephone with the British Foreign Secretary, Jack Straw, in an effort to coordinate policy.

Straw is due in the region next week. Powell's deputy Armitage will head for the area June 4, Reeker said.

"It's important for India and Pakistan to resume a productive dialogue over the issues that divide them, and that includes Kashmir," Reeker said. "An important component to this process is an end to infiltration into Kashmir, and as we've done before, we call upon Pakistan to do all it can to achieve this objective."

The administration is seeking an end to shelling in the disputed territory and urging Pakistan to curb the influx of Islamic militants.

Traveling in Europe with Bush, national security assistant Condoleezza Rice telephoned her Indian and Pakistani counterparts Thursday, as she had on Wednesday, to urge calm.

A senior White House official said the calls by Powell and Rice yielded some positive signs. But the official, speaking on condition of anonymity, declined to be specific.

At a news conference in Berlin, Bush said he and German Chancellor Gerhard Schroeder spent a lot of time in their meeting Thursday discussing the India-Pakistan situation.

Schroeder said he and Bush agreed "that we have to do whatever we can to bring a peaceful solution to this conflict. I mean, we must make sure that no further escalation happens over there."

Rumsfeld said the tensions between India and Pakistan were drawing Pakistani soldiers away from the border with Afghanistan where they were guarding against the influx of Al Qaeda fighters.

"It's unfortunate," he said. "It is a very porous border. It really permits people, the Al Qaeda and Taliban, to move across and that's unhelpful to us."