SEOUL, South Korea — North Korea said on Sunday that it had conducted a “very important test” at its missile-engine test and satellite-launch site, another sign of the country’s escalating pressure on the United States to make further concessions before a Dec. 31 deadline set by its leader, Kim Jong-un.
The test was carried out on Saturday at the Sohae Satellite Launching Ground, referring to the Tongchang-ri site near the North Korean border with China, a spokesman for the North’s Academy of National Defense Science said in a statement that was carried by the official Korean Central News Agency.
The brief statement provided no further details. But analysts said North Korea had most likely tested a new type of engine for long-range ballistic missiles.
The academy reported “the results of the successful test of great significance” to the Central Committee of North Korea’s ruling Workers’ Party, the spokesman said. The spokesman said that the successful test “will have an important effect on changing the strategic position” of North Korea “once again in the near future.”
North Korea has used the Tongchang-ri site to test rocket engines and launch satellite-delivery vehicles, accumulating technology that Washington said it then used to build and test long-range ballistic missiles. A series of resolutions by the United Nations Security Council has banned the North from conducting tests that could be used to build ballistic missiles.
In March 2017, North Korea successfully tested a new high-thrust engine at Tongchang-ri that was used to launch intercontinental ballistic missiles, such as the Hwasong-14 and Hwasong-15, later that year.
Mr. Kim, the North Korean leader, met with President Trump in Singapore in June 2018 and agreed to “work toward complete denuclearization of the Korean Peninsula” in return for “new” relations and security guarantees from Washington. After the Singapore meeting, Mr. Trump said that Mr. Kim had promised to dismantle the Tongchang-ri facility as one of the first steps toward denuclearization.
But that has never happened.
As subsequent meetings with Mr. Trump and continuing negotiations between Pyongyang and Washington having failed to resolve differences over how to implement the broadly worded Singapore deal, Mr. Kim has grown increasingly impatient with negotiating.
In recent months, North Korea has conducted a series of tests of mostly short-range ballistic missiles and rockets. It has also issued a steady stream of statements warning that it might abandon diplomacy and resume more provocative weapons tests unless Washington provides a breakthrough in the stalled negotiations by the end of the year, the deadline set by Mr. Kim. The country has also rebuilt the missile-engine test facility at Tongchang-ri that it had earlier started dismantling.
Satellite images of the Tongchang-ri site in recent days indicate that North Korea may be preparing to resume testing rocket engines used to power satellite launchers and intercontinental ballistic missiles, according to CNN.
Officials and analysts in Seoul also agreed that the latest test at Tongchang-ri most likely involved a new missile engine.
Before Mr. Kim met with Mr. Trump last year, he announced a halt to all nuclear and intercontinental ballistic missile tests, or ICBMs, a self-imposed moratorium that Mr. Trump has repeatedly cited as one of his main achievements in his on-off diplomacy with Mr. Kim. But the moratorium did not cover missile-engine tests. So Mr. Kim can still claim that he has not shirked his pledge, while using such tests to send a warning to Washington that they could be followed by ICBM tests, analysts said.
Mr. Kim is scheduled to convene his party’s Central Committee this month to “discuss and decide on crucial issues,” given “the changed situation at home and abroad,” according to the North Korean state media.
Kim Dong-yub, a North Korea expert at the Seoul-based Institute for Far Eastern Studies, said the latest test may have involved a new type of ICBM engine that uses solid fuel.
North Korea’s existing ICBMs use liquid fuel. North Korea has been trying to convert its missiles from liquid fuel to solid, which is easier to transport and faster to load onto missiles, thus making it harder for the United States military to find and target its missiles before they are launched.
“North Korea is avoiding violations of its long-range missile test moratorium for now, but it is still improving the propulsion and precision of its missiles so that it can claim a credible nuclear deterrent,” said Leif-Eric Easley, associate professor of international studies at Ewha Womans University in Seoul. “The Kim regime knows that U.S. surveillance flights and satellites are watching. So with the activity at Sohae, Pyongyang is also trying to raise international concerns that it may intensify provocations and walk away from denuclearization talks next year.”
Hours before North Korea’s announcement on Sunday, its ambassador to the United Nations said that denuclearization was off the negotiating table with the United States and lengthy talks with Washington were not needed.
The North Korean envoy, Kim Song, said on Saturday that the “sustained and substantial dialogue” sought by the United States was a “timesaving trick” to suit its domestic political agenda, a reference to Mr. Trump’s 2020 re-election bid. “We do not need to have lengthy talks with the U.S. now and denuclearization is already gone out of the negotiating table,” he said in a statement distributed to reporters.
North Korea has recently said that Washington should not “dream of” negotiating denuclearization unless it first abandoned its “hostile policies.”
Mr. Trump has sought to play down the increasingly strident remarks from North Korea, reiterating that he and Mr. Kim were on good terms.
“We’ll see about North Korea,” Mr. Trump told reporters at the White House on Saturday. “I’d be surprised if North Korea acted hostilely,”
“The relationship is very good, but you know, there is certain hostility, there’s no question about it,” he added.
Mr. Trump has said that he can achieve what his predecessors could not: an end to nuclear threats from North Korea. He has met Mr. Kim three times to that effect. But North Korea is nowhere near giving up its nuclear weapons program.
Instead, Mr. Kim has warned that unless the United States lifts United Nations sanctions, which have stymied his ambitions for rapid economic growth, North Korea will abandon diplomacy and “find a new way.”