North Korea (searchtest-fired an anti-ship missile off its east coast Monday as President Bush (search) and other leaders opened an Asian summit, the communist country's latest military exercise amid tensions over its nuclear program.

South Korea's Joint Chiefs of Staff on Monday declined to further identify the type of missile, but said North Korea has fired the same type two or three times this year. U.S. officials are more concerned about North Korea's efforts to develop a missile that could reach the United States.

"The land-to-ship missile North Korea test-fired today is seen as part of its annual exercise," said a spokesman for the Joint Chiefs of Staff in Seoul, speaking on customary condition of anonymity.

On Tuesday, Japan (search) said it suspects that North Korea may have test-fired a missile off its eastern coast for a second straight day. The government said it was trying to confirm the information.

Monday's test came as Bush, meeting in Bangkok, Thailand, promoted a plan in which the United States, China, Russia, Japan and South Korea would jointly give North Korea written assurances it wouldn't be attacked, in exchange for its promise to dismantle its nuclear program.

Senior Bush administration officials, also speaking on condition of anonymity, said they'd concluded the missile test was a deliberately provocative action intended to grab attention.

On Sunday, Bush dismissed North Korea's demand the United States sign a nonaggression pact in exchange for nuclear concessions.

Monday's launch was the first by North Korea since a reported test in April. Tensions have risen in the region since last October, when Washington said North Korea admitted having a clandestine nuclear program.

Bush met Monday with South Korean President Roh Moo-hyun and cited "good progress" in winning support for a new diplomatic overture to North Korea. They issued a joint statement calling for quick resumption of six-nation talks on Pyongyang's nuclear program, and urged the reclusive communist regime "to refrain from any action which would exacerbate the situation."

Representatives from the United States, the two Koreas, China, Japan and Russia met in Beijing in August to discuss ways to end the nuclear crisis. But the meeting ended without agreement on when to hold another round of talks because of strident differences between North Korea and Washington.

In Tokyo, Cabinet Office spokesman Yukinori Morita and the Defense Agency said the Japanese government had received a report of a land-to-ship missile being fired into the sea between North Korea and Japan around noon on Monday, but had not verified the information.

The missile would not have posed any immediate security threat to neighboring countries, a Japanese Defense Agency official said, adding that the missile reportedly had a range of about 60 miles.

North Korea test-fired two short-range anti-ship missiles in late February and early March. In those tests, North Korea fired the missiles at targets about 70 miles off its east coast. Washington and South Korea have criticized the tests as attempts to force the United States into direct talks.

In April, U.S. officials said North Korea test-fired another short-range anti-ship missile off its west coast, in apparent response to the launching of spy satellites by Tokyo to monitor the isolated communist nation days earlier.