SEOUL, South Korea — In hailing the deal he reached with Kim Jong-un this summer in Singapore, President Trump said it “largely solved” the North Korean nuclear crisis.

He has since doubled down on that statement, most recently on Tuesday. “People don’t realize the importance of the first meeting,” he said. “I mean, we said, ‘Point No. 1: denuclearization.’ They’ve agreed to denuclearization.”

It was actually the third bullet point in the four-point Singapore agreement, and for the North Koreans, the order of those bullet points is everything. It will only agree to denuclearize once Washington commits to the first and second points: Mr. Trump’s promise to build “new” relations and a “peace regime” in Korea — and makes North Korea feel secure enough to disarm.

The standoff shows how North Korea has turned the deal Mr. Trump signed with its leader, Mr. Kim, into one of its most effective cudgels in talks with Washington over denuclearization, ceaselessly flaunting it to force American concessions.