North Korea test-fired what are believed to have been two short-range ballistic missiles on Friday, the general staff of the South Korean armed forces says.
The launches came after North Korea's Foreign Ministry accused the US of "provocation" for imposing further sanctions on Pyongyang for its weapons programme and threatened Washington with a clear response.
The test was the third carried out by North Korea within 10 days. South Korea's National Security Council expressed its "deep regret" about North Korea's continued missile launches.
"That's the problem with being implacable foes - no one has any incentive to treat you as anything more than an obstacle to be overcome."