U.S. President Barack Obama said Friday that the alliance between Japan and America will endure for the foreseeable future as a linchpin of the future of East Asia.

"I began my trip here in Tokyo because the U.S. Japan alliance is a foundation for peace and prosperity throughout East Asia," Obama said at a news conference after meeting with Japanese Prime Minister Yukio Hatoyama. "I am confident that we will continue to strengthen the U.S.-Japan alliance for future generations," he said.

The news conference was a reaffirmation of the strong ties between the two nations, but the tensions on the Status of Forces Agreement (SOFA) were clear.

"It will be a very difficult issue, but as time goes by I think it will become more difficult to resolve the issue. So we understand we need to resolve the issue as soon as possible and we will work to do that," said Hatoyama, for his part.

Obama said that working toward reaching an agreement on this issue was essential.

U.S. President Barack Obama arrived Friday in Tokyo, kicking off a two-day visit to Japan.

Japan is the first leg of Obama's four-country Asian tour, which will also take him to Singapore, China and South Korea.