Story highlights The missiles were no threat to the US mainland or Guam, US officials say

South Korea-US military exercises are underway

Pyongyang, North Korea (CNN) North Korea launched a barrage of missiles Saturday, less than one week after US Secretary of State Rex Tillerson praised the country for showing 'restraint' in its weapons program.

Pyongyang fired three short-range ballistic missiles from the Kangwon province, the US Pacific Command said. The launches occurred in the midst of the US and South Korea's annual military exercises.

US Pacific Command, in its initial assessment of the launch on Saturday, said North Korea's first and third missiles failed in flight. It later amended its statement to say the missiles flew "approximately 250 kilometers in a northeastern direction."

The second missile appeared to have blown up almost immediately at launch, the command said.

"We will continue to work with our interagency partners on a more detailed assessment of this latest launch and we will provide a public update if warranted," command spokesman Cmdr. David Benham said in a statement.