North Korean leader Kim Jong Un inspected the demonstration of a "new-type tactical guided weapon" on Thursday as a warning to South Korea to stop importing high-tech weapons and conducting joint military exercises, state media KCNA said on Friday.

North Korea test-fired two new short-range ballistic missiles on Thursday, South Korean officials said, its first missile test since Kim and U.S. President Donald Trump agreed to revive denuclearisation talks last month.

The KCNA report did not mention Trump or the United States, but it said Kim criticised South Korean authorities for carrying on with joint exercises, which are usually conducted with U.S. troops.

"We cannot but develop nonstop super-powerful weapon systems to remove the potential and direct threats to the security of our country that exist in the South," Kim said, according to KCNA.

He accused South Koreans of "double dealing" for saying they support peace but simultaneously importing new weapons and conducting military drills.

South Korea's leader should stop such "suicidal acts" and "should not make a mistake of ignoring the warning," Kim said.

Kim said he was "satisfied" with the rapid response and low-altitude trajectory of the weapon, which he said would make it difficult to intercept.

Seoul's National Security Council said on Thursday it believed the missiles were a new type of ballistic missile, but it would make a final assessment with the United States.

South Korea, which had backed efforts by North Korea and the United States to end years of hostility, on Thursday urged Pyongyang to stop acts that are unhelpful to easing tension and said the tests posed a military threat. The U.S. State Department urged Pyongyang to refrain from further provocations and said it still hoped for a resumption of working-level talks on North Korea's denuclearization.