U.S. doubts North Korean missile claim

• NEW: South Korea says the launch showed improvements in an existing weapon


• KCNA: North Korea fires "cutting-edge ultra-precision tactical guided missiles"


• "There is no indication of new North Korean technology," says a U.S. defense official


• According to the U.S. and South Korea, North Korea launched three projectiles

Washington (CNN) -- A U.S. defense official on Thursday dismissed North Korea's claim of testing newly developed missiles.

"There is no indication of new North Korean technology," said the official, who spoke on the condition of anonymity.

The U.S. military monitored what the defense official described as the routine launch of short-range missiles.

Earlier, North Korea's state-run news agency KCNA reported that leader Kim Jong Un had "guided the test-fire of newly developed cutting-edge ultra-precision tactical guided missiles."

N. Korea tests 'cutting-edge missiles'

Third U.S. tourist detained in N. Korea

Can North Korea take this Hollywood joke?

"At the central monitoring post he acquainted himself with the tactical and technological information of the newly developed guided missiles before giving an order to test-fire them.

"The moment the guided missiles soared into the sky with thunderous roar," the report read.

According to the U.S. and South Korean governments, North Korea launched three projectiles from its southeastern coast.

"I think we're always concerned whenever North Korea launches anything," said U.S. State Department spokeswoman Marie Harf.

She added: "We're monitoring the situation, and we're still evaluating the available information to identify the exact type of projectile that may have been launched."

Kim Min-seok, a spokesman for the South Korean Defense Ministry, said Friday that what North Korea launched appears to have been an improvement of an existing weapon, rather than an entirely new technology.

The improvements were in the weapon's range and the guided technology, he told a regular news briefing.

From the North Korean military's point of view, the weapon may be new, Kim said, "but if you look at the international trend, this weapon technology was developed before."

North Korea ups stakes with latest missile launch

INTERACTIVE: North Korea's missile capacities

CNN's Dana Ford and K.J. Kwon contributed to this report.