The United States will strengthen its relationship with Japan as part of its policy to seek greater engagement with Asia during the second term of President Barack Obama, a senior White House official said Thursday.

National Security Adviser Tom Donilon said at a think tank seminar that enhancing relations with allies in Asia, including Japan and South Korea, is one of the five key tasks the administration has laid out.

U.S. ties with Japan and South Korea have "really advanced to an unprecedented level," and these alliances are "unique American assets" in the region, Donilon said.

The other four tasks are building closer relations with emerging Asian economies, deeper engagement with regional institutions such as the Association of Southeast Asian Nations, pursuing a stable and constructive relationship with China and promoting regional economic frameworks such as the Asia-Pacific Economic Cooperation forum, he said.

Donilon made the remarks prior to Obama's visit to three Southeast Asian countries starting Saturday, his first overseas trip since winning a second term last week.

Obama's decision to travel to Asia first "speaks to the importance he places on the region, its centrality to so many of our national security issues and priorities," the White House official said.

During his visit to Myanmar, Obama will meet with President Thein Sein and other figures, including Aung San Suu Kyi, to endorse and support reforms that are currently under way, Donilon said.

The president's visit "reflects his conviction that engagement is the best way to encourage Burmese authorities to take further action," he said.