WASHINGTON — The goal of a diplomatic meeting set for Thursday seemed simple: Nail down a plan for a second summit between President Trump and the North Korean leader, Kim Jong-un.
But finalizing the meeting itself — between Mike Pompeo, the secretary of state, and one of Mr. Kim’s top compatriots — proved harder than expected. At midnight on Wednesday, the State Department announced that it had been canceled.
“Ongoing conversations continue to take place,” the statement said tersely.
The cancellation leaves little doubt that the diplomatic process between the United States and North Korea is now mired in quicksand after peaking in Singapore with the initial summit between the two leaders. There are mismatched demands and expectations on both sides, and the pitfalls have only gotten more obvious in recent weeks.
At the White House later Wednesday, Mr. Trump said the meeting would be rescheduled and insisted that “we’re very happy with how it’s going with North Korea.”
“We’re in no rush,” he said, adding that he expected to again sit down with Mr. Kim early next year. “The sanctions are on. The missiles have stopped, the rockets have stopped. The hostages are home.”
Last Friday, North Korea veered toward hostility as its foreign ministry warned the country would return to a policy of strengthening its nuclear force if the Trump administration did not lift economic sanctions. That announcement did not bode well for prospects of a successful meeting between Mr. Pompeo and the North Korean party official, Kim Yong-chol, a hard-line general and former intelligence chief.
North Korea suspended its nuclear tests in September 2017, but American experts believe Pyongyang continues to develop fissile material, has 30 to 60 nuclear warheads and might have a ballistic missile capable of hitting the continental United States. North Korea can produce enough missile material for six to seven bombs annually, said Siegfried Hecker, a Stanford University nuclear scientist.
Mr. Trump has said he and Kim Jong-un “fell in love” after meeting in Singapore and that North Korea was moving forward with promises to denuclearize, the reality is otherwise, according to findings by American intelligence officials. North Korea is still refusing to turn over an accounting of its nuclear assets to the United States and other nations, a demand that the Trump administration sees as an important step toward denuclearization.
Instead, North Korean officials say the United States must agree first to formally declare the end of the Korean War, which halted with an armistice in 1953. The South Korean government, intent on improving relations with North Korea, has also pushed for this.
“I think Pompeo again is in a bit of pickle,” said Jung H. Pak, an expert on North Korea at the Brookings Institution and a former C.I.A. analyst. “North Korea has been clear about what they’re not willing to do.”
In a statement on Monday, Heather Nauert, the chief State Department spokeswoman, said Mr. Pompeo and Stephen Biegun, the special representative for North Korea, planned to discuss steps toward progress in the Thursday meeting with Kim Yong-chol, the envoy from Pyongyang.
Among the four main points agreed to in Singapore, Ms. Nauert said, was “the final, fully verified denuclearization of the DPRK,” or the Democratic People’s Republic of North Korea, the formal name of North Korea.
But that is a notable change in wording from the agreement reached in June.
The third of the four points in that agreement said North Korea “commits to work toward complete denuclearization of the Korean Peninsula,” according to the White House statement from the summit. North Korea has interpreted this as meaning all sides agreeing to give up arms.
North Korean officials also have stressed the two points ahead of denuclearization to argue that forging a formal declaration to the end of the Korean War happen first. Those points called on the United States and North Korea to establish a new relationship with the aim of “peace and prosperity” and try to build “a lasting and stable peace regime on the Korean Peninsula.”
Last month, Mr. Pompeo met with the North Korean leader in Pyongyang. The chief American diplomat described it as a “good trip” and announced a modest agreement by Mr. Kim to allow outside inspectors to enter Punggye-Ri, a network of underground tunnels where North Korea has conducted all its nuclear tests.
Ms. Pak said North Korea’s offers so far have been minor compared to what it is asking of the United States in return — the formal end-of-war declaration and an easing of harsh economic sanctions.
“Because the North Korea nuclear program is so advanced, this is like North Korea offering to sell us Windows 97 at a price higher than it warrants,” Ms. Pak said. She said Mr. Trump had already given away important leverage by agreeing to stop joint military exercises with South Korea.
After Mr. Pompeo’s trip in October, Mr. Biegun was supposed to meet with Choe Son-hui, North Korea’s vice foreign minister. But that never happened, marking another sign of lackluster diplomacy.
While Mr. Trump has generally been effusive about the warming relations, there have been rough patches throughout.
Mr. Pompeo was kept waiting when he met with Kim Yong-chol in July in Pyongyang. Afterward, the North Korean government said the Trump administration was pushing a “unilateral and gangster-like demand for denuclearization.” A month later, in August, Mr. Trump abruptly canceled a trip Mr. Pompeo was scheduled to make to North Korea.
Talks between North Korea and the administration of President Moon Jae-in of South Korea have been going much more smoothly.
Mr. Moon is trying to arrange a meeting by year’s end with Kim Jong-un in Seoul, following on the South Korean president’s landmark visit to North Korea in September. That would be their fourth meeting this year.
On Nov. 3, a commentary in Rodong Sinmun, an official Workers’ Party newspaper in North Korea, encouraged the two Koreas to move forward with an end-of-war declaration. It described a “vital demand of the Korean nation” that the two governments “ease the military tension on the Korean Peninsula and remove the danger of war.”
“On the inter-Korean process, it’s been continued progress on all fronts,” said John Delury, a professor at Yonsei University in Seoul. “The Americans should catch up to the South Koreans.”
On Friday, the subject of North Korea will no doubt come up again when Mr. Pompeo meets in Washington with Yang Jiechi, a senior Chinese foreign policy official. Jim Mattis, the defense secretary, is expected to meet the same day with General Wei Fenghe, China’s defense minister.
The meetings are part of a regular dialogue that Mr. Trump and Xi Jinping, president of China, agreed to in 2017. Since then, relations between the two nations have worsened, mostly because of a trade war that Mr. Trump started.