North Korea fired a new type of short-range ballistic missile in two launches into the sea Thursday, South Korean officials said. They were North Korea’s first weapons launches in more than two months and appeared to be a pressuring tactic as Pyongyang and Washington struggle to restart nuclear negotiations.

The South’s Joint Chiefs of Staff said the missiles were fired from near the eastern coastal town of Wonsan and flew about 430 kilometers and 690 kilometers respectively before landing off the country’s east coast.

The Joint Chiefs of Staff described both missiles as short-range but didn’t elaborate. But after a national security council meeting later Thursday, South Korea’s presidential Blue House said the weapons North Korea launched were assessed as “a new kind of short-range ballistic missiles.”

North Korea is banned by UN Security Council resolutions from engaging in any launch using ballistic technology. So North Korea could face international condemnation over the latest launches. But it’s still unlikely for the North, already under 11 rounds of UN sanctions, to be hit with fresh punitive measures because the U.N. council has typically imposed new sanctions only when the North conducted long-range ballistic launches, not short-range ballistic launches.

A South Korean defense official, requesting anonymity because of department rules, said that an initial analysis showed both missiles were fired from mobile launchers and flew at a maximum altitude of 50 kilometers.The North is unhappy over planned US-South Korean military drills that it says are preparation for an invasion. The missile tests may be meant as a warning to Washington.

They came as many in the United States were focused on testimony before Congress by Robert Mueller, the former special counsel, about his two-year probe into Russian election interference. A day earlier, U.S. national security adviser John Bolton left Seoul after agreeing with South Korean officials to work closely to achieve North Korea’s denuclearization.

“North Korea appears to be thinking its diplomacy with the US isn’t proceeding in a way that they want. So they’ve fired missiles to get the table to turn in their favor,” said analyst Kim Dae-young at the Korea Research Institute for National Strategy.

But North Korea doesn’t appear to be pulling away from US-led diplomacy aimed at curbing its nuclear program, analysts say. The relatively short distance travelled by the missiles suggests the launches were not intended as a major provocation, unlike a test of a long-range missile capable of reaching the U.S. mainland.

North Korea has been urging the U.S. and South Korea to scrap their summertime military drills. Last week, the North said it may lift its 20-month suspension of nuclear and long-range missile tests in response to the drills. Seoul said Wednesday North Korea was refusing to accept its offer to send 50,000 tons of rice through an international agency to protest the drills.

Some experts say North Korea is trying to get an upper hand ahead of a possible resumption of talks. Pyongyang wants widespread sanctions relief so it can revive its dilapidated economy. U.S. officials demand North Korea first take significant steps toward disarmament before they will relinquish the leverage provided by the sanctions.