The first negotiations in eight months between the Trump administration and North Korea on carrying out commitments to begin dismantling the North’s nuclear program broke down only hours after they began in Stockholm on Saturday, the North Koreans said. It was the latest indication that President Trump’s signature diplomatic initiative has stalled.

“The negotiation did not live up to our expectations and broke down,” the chief North Korean negotiator, Kim Myong-gil, said, according to Yonhap, the South Korean news agency. Mr. Kim added that the United States had arrived “empty-handed” and had “not discarded its old stance and attitude.”

The State Department, in a carefully worded statement, did not say the talks failed, and warned that the “early comments” from the North “do not reflect the content or the spirit of today’s 8½ hour discussion.” The statement continued: “The U.S. brought creative ideas and had good discussions” with its North Korean counterparts.

Eager not to be cast as the obstacle to progress, the State Department also said its delegation previewed new proposals not only on denuclearization, but in formally ending the Korean War. State Department officials did not say how the North Korean negotiating team reacted.

Despite the rosy statement from the American side, it remained clear that both sides had walked away on the first day of talks. And although the American negotiators said they were willing to come back in two weeks, the North Koreans made no such statement.

The breakdown in the talks, the first since President Trump and Chairman Kim Jong-un of North Korea walked away from a summit meeting in Hanoi in February, was hardly surprising. Despite Mr. Trump’s frequent optimistic statements about his relationship with Mr. Kim and what he has termed Mr. Kim’s “beautiful letters” to him, the North has accelerated its testing of missiles and added to its stockpile of nuclear fuel.

One objective of the new talks, according to some administration officials, was to test out new proposals that would amount to a temporary freeze of nuclear activity, so that the North’s capability did not increase while the talks drag on. Mr. Trump’s failure to negotiate a freeze when he first met Mr. Kim in Singapore in June 2018 — the first meeting between an American president and a North Korean leader — is considered by many experts to be a key flaw in his negotiating approach.

It is not clear if the new talks even broached the temporary freeze. The State Department’s chief negotiator, Stephen Biegun, has said little about the specifics of American proposals, but it was clear they involve a more incremental approach to denuclearization. Mr. Trump once expressed optimism that the North would be well into the denuclearization process within six months of the Singapore meeting.

In recent days one of Mr. Trump’s former national security advisers, John R. Bolton, delivered a stinging appraisal of Mr. Trump’s approach without ever naming the president, who fired him a month ago.

Mr. Bolton said he believed that Mr. Kim had no intention of ever giving up his weapons, a statement largely in accord with years of American intelligence estimates dating to before Mr. Trump was elected. Mr. Bolton said added that there was little use in the negotiations, which he was excluded from at the end of his time in office, apparently because Mr. Trump believed Mr. Bolton’s hawkish views were more likely to lead to a conflict than to a negotiated settlement.

“I don’t think the North Koreans will ever voluntarily give up enough” to make the negotiations fruitful, Mr. Bolton said last Monday at the Center for Strategic and International Studies in Washington. “There is no basis to trust any promise that regime makes.”

Mr. Trump’s theory is that the issue can be solved only by direct meetings between the leaders of the two nations, since decades of lower-level talks either broke down or resulted in agreements that fractured apart within a few years. The most notable success came from a 1994 agreement struck by the Clinton administration, more than a decade before the North tested its first nuclear device. Even that agreement fell apart within six years, after the United States and South Korea caught the North secretly pursuing uranium enrichment, one of the two pathways to building a nuclear weapon.

Mr. Kim may be betting that Mr. Trump needs a breakthrough before next year’s American presidential election, and so he is testing to see if he can get the Trump administration to lift the onerous sanctions on North Korea that have squeezed its export revenues for the past three years. In Hanoi, Mr. Kim proposed closing down the country’s main nuclear production facility at Yongbyon in return for an end to those sanctions.

Mr. Trump, while tempted to accept the deal, was persuaded otherwise by Mr. Bolton and Secretary of State Mike Pompeo that he would be accused of leaving the North with production facilities outside of the Yongbyon plant, and with an arsenal of 30 to 60 weapons. Mr. Kim has not included the dismantlement of any of his nuclear weapons or missiles as part of his offer. The two men walked away from Hanoi, Mr. Kim’s negotiators were fired, and talks stalled.

Mr. Biegun’s challenge in the Stockholm talks was to find some phased pathway to begin the disarmament process, and that failed.