The Korean Central News Agency released Wednesday photos of North Korea's new tactical guided missile being launched in a demonstration firing a day before. Yonhap

The guided rockets that North Korea claimed to have fired in recent weeks are no different from missiles, a U.S. expert said Tuesday, endorsing South Korea's assessment that what the communist nation fired were short-range ballistic missiles.

Vann H. Van Diepen, a former U.S. State Department and intelligence official with expertise on weapons of mass destruction issues, made the case on 38 North, a website providing analysis on North Korea.

He said that the difference between a rocket and a missile is in part political because the South wants to highlight the North's violation of U.N. Security Council resolutions in its four rounds of launches since July 25. The North, he said, wants to underscore that the tests do not violate the resolutions and are not inconsistent with its pledge to refrain from long-range missile tests.

"From a technical standpoint, however, a 'guided' rocket is a 'missile' (the presence of guidance is what distinguishes a 'rocket' from a 'missile'), and a missile that 'has a ballistic trajectory over most of its flight path' is a 'ballistic missile,'" Van Diepen said.