The United States is expecting to beef up relations with Japan's new government in various fields, a senior US official said in Washington on Wednesday.

"We congratulate Democratic Party of Japan Leader Yukio Hatoyama on his appointment to prime minister in Japan and the formation of a new government," State Department spokesman Ian Kelly told reporters.

Describing the US-Japan alliance as "a cornerstone of peace and security in Asia," Kelly said "The United States looks forward to early and close consultations with the new Japanese government on a wide range of bilateral, regional and global issues."

Kurt Campbell, assistant secretary of state for east Asia and Pacific affairs, will leave for Tokyo, Japan later Wednesday for talks with members of the new government, the spokesman said.

Kelly did not give any details about Campbell's scheduled talks in Japan. But he said that the United States wants Japan to continue to help with Afghanistan.

Democratic Party of Japan (DPJ) President Yukio Hatoyama was elected as Japan's 93rd prime minister at a special Diet session Wednesday, succeeding Taro Aso of the Liberal Democratic Party (LDP).

The Obama administration pledged to keep a "strong alliance" with Japan's new government headed by Prime Minister Hatoyama.

"We are confident that the strong US-Japan Alliance and the close partnership between our two countries will continue to flourish under the leadership of the next government in Tokyo," White House spokesman Robert Gibbs said early this month.