South Korean and international news media are reporting that North Korea has fired a ballistic missile into the sea near the Korean Peninsula. If true, this is the latest escalation in a four-month dispute over North Korea's nuclear programs.

The missile firing appears to be the first into open waters since 1998, when North Korea fired a missile over Japan and into the Pacific Ocean.

According to South Korean and international news media Tuesday, the missile was fired Monday.

The missile launch came less than 24 hours before South Korea's new president, Roh Moo-hyun, is inaugurated. He takes office Tuesday morning.

Since October, North Korea has been locked in an international dispute over U.S. statements that Pyongyang was violating international treaties by secretly developing nuclear weapons. North Korea has responded by withdrawing from the nuclear Non-proliferation Treaty and issuing a series of belligerent statements.

Last week, a North Korean fighter jet crossed into South Korean airspace for the first time in 20 years. The North also has threatened to withdraw from the armistice that ended fighting in the Korean War in 1953.

U.S. military officials in South Korea said they were not aware of the reported missile launch.