The United States and Japan are vowing to keep their alliance strong at a time of change in both Washington and Tokyo.  The Japanese capital was the initial stop on Barack Obama's first trip to Asia as President of the United States.

It was a low-key arrival in a chilly rain.  And it came at a time of uncertainty in relations between the United States and Japan.

The new Japanese Prime Minister - Yukio Hatoyama - campaigned on a pledge to be less dependent on Washington.

He is seeking trade deals with other Asian countries, and is reviewing long-term U.S.-Japan military agreements.

But when they went before reporters after the meeting, President Obama downplayed any tensions.

"There should be no doubt as we move our nations in a new direction, our alliance will endure and our efforts will focus on  revitalizing that friendship so that it is even stronger and successful in meeting the challenges of the 21st century," President Obama said.

Prime Minister Hatoyama agreed.

Mr. Hatoyama announced plans for a review of U.S. - Japan relations leading up to 50th anniversary of the strategic alliance in 2010.

President Obama said the time is right to renew and refresh the partnership between Washington and Tokyo.

"It is essential for the United States, it is essential for Japan and essential for the Asia-Pacific region," the president said.

Their talks ended with pledges of increased cooperation in areas such as nuclear non-proliferation and climate change.

Both said they want to find a solution to the dispute over U.S. military basing rights on the southern island of Okinawa.    But Prime Minister Hatoyama made clear Japan will no longer refuel ships involved in the U.S.-led war in Afghanistan.

He said Japan decided it can do more good by providing Afghanistan with substantial civilian assistance - $5 billion over the next five years.

President Obama said he briefed the Japanese leader on his search for a revised Afghanistan strategy.  He said a decision will come soon.

"It will be one that is fully transparent so the American people understand exactly what we are doing and why we are doing it," Mr. Obama said.

The president said he also wants to send a clear message that the U.S. military commitment will not be open-ended.  He said the goal is to reach the point where the Afghan people can take care of their own security.