North Korea's latest missile launches did not violate a pledge its leader Kim Jong Un made to U.S. President Donald Trump, a senior U.S. official said on Thursday, but efforts to resume denuclearization talks remained in doubt.
Kim oversaw the first test firing of a "new-type large-calibre multiple launch guided rocket system" on Wednesday, North Korean state media reported.
It followed six days after the launch of two similar short-range ballistic missiles, North Korea's first tests since Kim and Trump met on June 30 and agreed to revive stalled denuclearization talks.
The latest launches were intended to put pressure on South Korea and the United States to stop upcoming military drills and came as diplomats criss-cross the region this week in the hope of restarting the talks.
"The firing of these missiles don't violate the pledge that Kim Jong Un made to the president about intercontinental-range ballistic missiles," U.S. national security adviser John Bolton said in an interview with Fox Business News.
"But you have to ask when the real diplomacy is going to begin, when the working-level discussions on denuclearization will begin," he said.
North Korea's tests of short-range missiles on Wednesday and last week came despite a meeting between Kim and Trump on June 30 at which they agreed to revive stalled talks.
Massachusetts Institute of Technology professor Vipin Narang said the missile tests were part of the North Korean leader's approach to diplomacy. "He's saying it will take more than a photo-op to get things moving."
The tests were a stark reminder that every day the United States and its allies fail to secure an agreement is a day that North Korea continues to improve and expand its nuclear and missile arsenals, he said.
U.S. officials have played down the tests. Secretary of State Mike Pompeo said earlier this week he still hoped that talks would start soon, including possibly on the sidelines of a Southeast Asian security forum in Bangkok this week.
However, Bolton said there had been no response from North Korea. "We're still waiting to hear from North Korea," he said.
A summit between Trump and Kim in Vietnam in February collapsed after they failed to reconcile differences between Washington's demands for Pyongyang's complete denuclearization and North Korean demands for relief of extensive international sanctions.
North Korea did not describe the newest weapons in detail or immediately release photos, but South Korean military officials have characterized them as ballistic missiles. Such weapons could violate United Nations resolutions designed to pressure Pyongyang to give up its nuclear weapons and missile programs.
Britain, Germany and France have asked the United Nations Security Council to meet behind closed doors on Thursday to discuss the latest missile launches, diplomats said.
U.N. Secretary-General Antonio Guterres believed the missile launches were "just another reminder of the importance of restarting talks on the denuclearization of the Korean peninsula", U.N. spokesman Stephane Dujarric told reporters.
Wednesday's test verified the combat effectiveness of the overall system and Kim predicted "it would be an inescapable distress to the forces becoming a fat target of the weapon," North Korean state news agency KCNA said.
It said the rocket system would play a major role in ground military operations.
South Korea's Joint Chiefs of Staff (JCS) said the North had fired ballistic missiles that flew about 250 km (155 miles).
South Korean nuclear envoy Lee Do-hoon met U.S. Special Representative for North Korea Stephen Biegun on Wednesday on the sidelines of the Association of Southeast Asian Nations (ASEAN) Regional Forum in Bangkok.
South Korea's foreign ministry said in a statement on Thursday they discussed the missile tests and vowed diplomatic efforts for an early restart of working-level talks.
North Korean Foreign Minister Ri Yong Ho cancelled a planned visit to the ASEAN forum but Pompeo said the Americans were still open to a meeting.
The United States does not plan to make changes to this month's military drill with South Korea, a senior U.S. defense official said on Wednesday, despite the recent missile tests.
"We have to do two things: we have to give the diplomats appropriate space for their diplomacy and help create an environment that is conducive to the talks when they resume ... and we have to maintain readiness," the U.S. official said.