South Korean and U.S. intelligence have detected suspicious vehicle movement in and out of a major North Korean missile test site on its eastern coast.

A government source in Seoul said Sunday military intelligence has spotted movement by several large vehicles in the Gitdaeryeong area, pointing to possible preparation for another missile test.

An intelligence source said the North could take additional provocative steps, including missile launches or a nuclear test, timed with the upcoming summit between South Korean President Roh Moo-hyun and U.S. President George W. Bush in Washington.

The source also warned of a significant impact if the North proceeds with missile or nuclear tests.

On Saturday, the U.S. Missile Defense Agency announced a successful test of its missile defense system, intercepting a target projectile with the size and speed of a North Korean missile.

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