"I would be very disappointed if that were happening," he told reporters. "It's a very early report. We're the ones that put it out. But I would be very, very disappointed in Chairman Kim, and I don't think I will be."

"We'll take a look," he said. "It'll ultimately get solved."

Trump and North Korean leader Kim Jong-un held their second summit in Hanoi, Vietnam, last week to negotiate a deal on dismantling the regime's nuclear weapons program in exchange for sanctions relief.

The summit was cut short without an agreement due to differences over the extent of denuclearization and sanctions relief each side could commit to.

The North Korean leader offered to dismantle the Sohae facility during his first summit with Trump in Singapore in June, and again at his third summit with South Korean President Moon Jae-in in September.

Dismantling activity began some time after the Singapore summit and then stopped in August, according to researchers.

"On the launch pad, the rail-mounted transfer building is being reassembled," 38 North, a project of the Stimson Center think tank, said Tuesday. "At the engine test stand, it appears that the engine support structure is being reassembled."

Commercial satellite imagery indicates the rebuilding started sometime between Feb. 16 and March 2, the report said. (Yonhap)