The top U.S. diplomat to East Asia is preparing for a four-nation tour next week.

Kurt Campbell, the assistant secretary of State for East Asian and Pacific Affairs, leaves Sunday for Beijing where he will attend a series of meetings on cooperation in the region. He is also expected to discuss concerns about North Korea and Iran.

From China, Campbell will travel to Mongolia and then Indonesia, where he will meet with other senior officials in preparation for the coming East Asia Summit and the ASEAN Regional Forum.

Campbell will also make a stop in South Korea before returning to Washington.

Campbell last traveled to the region in March, when he visited Japan, Mongolia and South Korea.

Last month, Campbell told an audience in Washington that the U.S. government will be working with Asian countries to improve education, health, and the well being of their people.

He noted that southeast Asia has made significant progress in the past decade, and that the 10-nation ASEAN group has developed into a strong institution. He praised ASEAN's role in tackling arms proliferation, Burma's human rights record and regional maritime security.

He also said Washington is not in competition for regional dominance with China, but rather seeks its cooperation toward solving shared problems.