Japan is not seeking new friction with China after Beijing protested a joint Japan-US declaration expanding the scope of their alliance by declaring concern over Taiwan, Prime Minister Junichiro Koizumi says.

Japan and the United States at weekend talks shared anxiety over tensions in the Taiwan Strait for the first time in their half-century alliance, which was built on US security guarantees for Japan after World War II.

But Koizumi said Japan was not stepping up pressure on China, saying the statement in Washington reflected Japan's position that there needed to be a "peaceful solution" in the Taiwan Strait.

"Our stance is consistent with the past," Koizumi told reporters.

China expressed "serious concern" about the statement on Taiwan.

Japan's Chief Cabinet Secretary Hiroyuki Hosoda appeared to say the United States was the main force putting Taiwan into the joint statement.

"The US concern is strong," Hosoda said. "For our country there is no new element in particular as we are hoping for peace (in the Taiwan Stait)."

China-Japan relations have worsened in recent months over a range of issues such as energy development in the East China Sea and Koizumi's repeated visits to the Yasukuni shrine, which honors Japanese war dead including war criminals.

The joint statement in Washington said Japan and the United States would "encourage the peaceful resolution of issues concerning the Taiwan Strait through dialogue."

It also called for "a cooperative relationship with China, welcoming the country to play a responsible and constructive role regionally as well as globally."

The statement was reached during talks between the US and Japanese foreign affairs and defense chiefs and is due to be signed later this year.

Kazuro Umezu, international relations professor at Nagoya Gakuin University, said tensions could mount between Japan and China before the statement was signed.

"China will probably pressure Japan (not to sign the joint document) in various ways," he said.

Japan has been pushing for a larger world role, in particular a permanent seat on the United Nations Security Council.

It has sent troops to Iraq and Indonesia on humanitarian missions despite its 1947 constitution which bars the keeping of a military.

But China has made clear it opposes a permanent seat for Japan, saying Tokyo needed to take further responsiblity for its wartime militarism.

Source: China Daily/agencies