WASHINGTON (AFP) - North Korea's launch of Scud missiles violated UN resolutions barring the firing of ballistic missiles, the Pentagon said on Friday.

The Defense Department initially said that the missile launch on Thursday was legal, but now says that was incorrect.

"Yesterday, I erroneously noted that these resolutions allow for North Korea to fire short range Scud missiles. That is not the case," Pentagon spokesman Colonel Steven Warren said in a statement.

UN Security Council resolutions 1718 and 1874 prohibit North Korea "from launching any ballistic missile, and this includes any Scud missile," he said.

The resolutions were adopted unanimously by the Security Council in 2006 and 2009 after nuclear tests carried out by Pyongyang.

The firing of the four short-range missiles off the east coast of North Korea coincided with US-South Korea joint military exercises.

Analysts said Pyongyang used the missile launch to convey its anger over the drills, which overlapped with the end of the first reunion in more than three years of families divided by the Korean War.

The Pentagon spokesman said the United States closely such monitors missile tests and called on the North to "refrain from actions that aggravate tensions and instead come into compliance with its international obligations and commitments."