PYONGYANG, North Korea — Secretary of State Mike Pompeo met with a top North Korean official for several hours on Friday in talks aimed at persuading the North to give up its nuclear and ballistic missile programs — a mission that, in conversations with at least two outside experts, he said was doomed from the outset.

The dire assessment from Mr. Pompeo comes despite the fact that he is one of the Trump administration’s most visible proponents of talks with North Korea.

Mr. Pompeo has repeatedly said he believes that the country’s young leader, Kim Jong-un, is serious about negotiations. He is making his third trip to Pyongyang, North Korea’s capital, even as others — including his rivals in the administration — have been more skeptical of the diplomatic efforts.

And he has tried to plan for success. He is traveling with North Asia experts from the State Department, Central Intelligence Agency and National Security Council, and is spending many hours in meetings that will continue on Saturday.