(CNN) President Donald Trump hopes to move beyond pleasantries next week in his second meeting with North Korean leader Kim Jong Un, officials said on Thursday, describing the follow-up talks as more intensive than an inaugural round last year in Singapore.

Even as he looks to convince Kim to abandon his nuclear program, however, Trump faces uncertainty about how willing the reclusive despot is to relinquish his stockpiles. A common definition of "denuclearization" doesn't yet exist, the officials said. And Kim hasn't committed to a timeline of any sort.

"I expect that there will be an ongoing process of give-and-take while we try to tease out exactly what is the full commitment," a senior administration official said Thursday, previewing the summit anonymously to reporters.

"I don't know if North Korea has made the choice yet to denuclearize, but the reason why we're engaged in this is because we believe there's a possibility that North Korea can make the choice to fully denuclearize," the official went on. "And that's why the President has assigned such a priority to engaging with them."

The comments reflected the uncertainty surrounding Trump's diplomatic gambit with North Korea, which he insists is proceeding apace even as intelligence officials say there is little to indicate Pyongyang will ever abandon its nuclear ambitions.

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