North Korea has almost completed rebuilding a long-range rocket site it had promised to close, Seoul lawmakers told reporters Friday after a closed-door meeting with South Korean intelligence officials.

According to Yonhap news agency, South Korea's National Intelligence Service (NIS) told the country's parliament that Pyongyang began work on the launch pad in February on its west coast before the U.S. and North Korea held a summit in Hanoi.

Reports had emerged early this month that Pyongyang was restoring the rocket launch site.

"The North started the reassembly work before the Hanoi summit. We cannot verify what that means," the NIS said.

Washington based think-tank Beyond Parallel claimed that its commercial satellite imagery acquired on March 2, 2019, showed that North Korea was "pursuing a rapid rebuilding" of the long-range rocket site at Sohae.

Pyongyang dissembled part of its rocket launch facilities in July 2018 after North Korean leader Kim Jong-un reportedly agreed to do so during his Singapore summit talks with U.S. President Donald Trump.

The restoration of the rocket launch site on the heels of Hanoi summit breakdown between Trump and Kim due to their failure to bridge differences over the scope of Pyongyang's denuclearization and Washington's sanctions relief.

"North Korea appears to be keeping its uranium enrichment facility in its mainstay nuclear complex in Yongbyon, north of Pyongyang, in normal operation," NIS said.

The agency also said it possessed the identities of a number of South Korean nationals who took part in a raid on the North Korean embassy in Spain last month.

A fugitive North Korean group which identifies itself as "Free Joseon" made off from the premises with computers and documents.