North Korea has fired a short-range surface-to-ship missile, according to officials from both South Korea and Japan.

A senior official for South Korea says the firing might be part of a scheduled military exercise, noting that North Korea had conducted several similar exercises this year. Japanese officials say the move poses no immediate security threats to neighboring countries.

But Asian leaders see the timing as significant.

The missile was fired as U.S. President George W. Bush and more than 20 other world leaders met for the annual Asia Pacific Economic Cooperation summit.

The North Korean nuclear crisis is one of the dominant topics of the APEC meeting in Bangkok. Mr. Bush met with South Korean President Roh Moo-hyun and the two called for North Korea to resume multi-nation talks on resolving the year-old standoff.

In the past few days, President Bush has also discussed the nuclear issue with Chinese President Hu Jintao and Japanese Prime Minister Junichiro Koizumi. Sunday, Mr. Bush reiterated his opposition to a bilateral non-aggression treaty with Pyongyang, but suggested that multi-lateral security assurances remain an option if North Korea halts its nuclear programs.

Japanese spokesman Yasuo Fukuda responded to President Bush's statement.

Mr. Fukuda welcomed the American idea, saying Japan appreciated the Bush administration's forward-looking stance.

But in the coming days, North Korea's missile launch could change Tokyo's attitude. Japan has grown increasingly concerned over North Korea's weapons arsenal and its missile capabilities.

It would take just a few minutes for a North Korean missile to reach Japan. In 1998, North Korea fired a long-range missile that flew over Japan and landed harmlessly in the ocean.

But it proved that North Korea's missile reach extended much farther than previous estimates. Its capability to deliver nuclear or other weapons of mass destruction by missile remains unknown.