WASHINGTON — President Trump has consistently touted the results of his North Korean diplomacy, insisting since his June summit meeting with Kim Jong-un that Pyongyang is no longer a nuclear threat and noting that its missile tests have stopped.

But like other foreign policy assertions from the White House, reality has proved more complicated.

North Korea has continued its work on missile and weapons programs since the leaders met, American officials say, including manufacturing new intercontinental ballistic missiles at a facility near Pyongyang, the capital, according to one Defense Department official. And North Korea continues to produce nuclear fuel, Secretary of State Mike Pompeo told senators last week.

Mr. Kim has little interest in giving up the North’s nuclear arsenal or rolling back its progress on ICBMs, experts who have long studied North Korea’s government and its missile programs believe. The North’s weapons work, including at a facility that creates ICBMs, has continued in the weeks after the summit meeting between Mr. Trump and Mr. Kim, said Jeffrey Lewis, an arms control expert at the Middlebury Institute of International Studies at Monterey in California.

American officials said they have not seen an increase in work in recent weeks but have watched the programs proceed at the same pace as in previous months. In particular, work on one to two ICBMs at Sanumdong, a missile manufacturing facility on the outskirts of Pyongyang, is consistent with the facility’s activity before the summit meeting, the Defense Department official said. The work on the new missiles was first reported by The Washington Post.