South Korea’s Joint Chiefs of Staff says that North Korea has launched “several” short-range missiles off its eastern coast, a likely sign of Pyongyang’s growing frustration at stalled diplomatic talks with Washington over its nuclear arsenal.

The military said in a statement Saturday that the missiles fired from Wonsan on North Korea’s east coast flew up to 200 kilometres before they landed in the water.

The South had previously said the North launched a single missile. 

South Korean and U.S. authorities are analyzing the details, but if it is confirmed as a firing of banned ballistic missiles, it will be the first such launch since the North’s November 2017 test of an intercontinental ballistic missile. That year saw a string of increasingly powerful weapon tests from the North, and a belligerent response from U.S. President Donald Trump that had many in the region fearing war.

The firings Saturday comes amid a diplomatic breakdown that has followed the failed summit earlier this year between Trump and North Korean leader Kim Jong-un over the North’s pursuit of a nuclear arsenal that can target the U.S. mainland. Experts believe that the North has viable shorter range nuclear armed missiles but still needs more tests to perfect its longer-range weapons.

During the diplomatic efforts that followed a rocky 2017, Kim said that the North would not test nuclear devices or ICBMs.

Short-range missiles would not violate that self-imposed moratorium. They may instead be a way to register his displeasure with Washington and the state of talks meant to provide sanctions relief for disarmament without having the diplomacy collapse.