WASHINGTON (Reuters) - President Donald Trump’s former chief of staff John Kelly has dismissed the U.S. president’s unprecedented engagement with North Korean leader Kim Jong Un as futile, saying he had never believed North Korea would give up its nuclear weapons and Pyongyang had played the United States to its benefit.

FILE PHOTO: White House chief of staff John Kelly listens as U.S. President Donald Trump meets with NATO Secretary General Jens Stoltenberg at the White House in Washington. U.S., May 17, 2018. REUTERS/Kevin Lamarque

Kelly, a former Marine Corps general who fell out with Trump and left the White House in December 2018, laid out his misgivings about the president’s policy approaches at Drew University in New Jersey on Wednesday night, the Atlantic magazine said in a report on its website.

“He will never give his nuclear weapons up,” the Atlantic quoted Kelly as saying of Kim, who Trump met three times between mid-2018 and June 2019 in fruitless attempts to persuade him otherwise.

“Again, President Trump tried - that’s one way to put it. But it didn’t work,” Kelly said. “I’m an optimist most of the time, but I’m also a realist, and I never did think Kim would do anything other than play us for a while, and he did that fairly effectively.”

Kelly’s remarks were similar to those of John Bolton, who Trump fired as his national security adviser last September, calling him a “disaster” on North Korea policy.

Kelly’s comments followed indications that Trump could be losing interest in his efforts on North Korea.

CNN on Monday quoted two sources familiar with the matter as saying that Trump, frustrated at the lack of progress, had told top foreign policy advisers he does not want another summit with Kim before the U.S. presidential election in November.

Talks between the two sides have stalled since last year over an inability to reconcile North Korea’s demands for relief from punishing sanctions and other concessions and U.S. demands for North Korea to denuclearize.

On Tuesday, the White House announced that Trump plans to nominate the State Department’s deputy special representative for North Korea to a post at the United Nations.

The senior U.S. envoy for North Korea, Stephen Biegun, took over the job of deputy secretary of state in December.

While North Korea has not tested a nuclear bomb or long-range missile since 2017, a confidential U.N. report seen by Reuters on Monday said it continued to enhance its nuclear and ballistic missile programs last year in breach of U.N. sanctions.

North Korea did not act on a threat to present the United States with a “Christmas surprise” that some feared could involve a return to testing, but Kim has warned that the world would soon see a “new strategic weapon.”