THE United States is prepared to ensure North Korean leader Kim Jong-un remains in power should the dictator make a historic nuclear deal with US President Donald Trump, according to Secretary of State Mike Pompeo.

“We will have to provide security assurances to be sure,” Mr Pompeo told Fox News Sunday. “This has been the trade-off that has been pending for 25 years. No president has ever put America in a position where the North Korean leadership thought that this was truly possible — that the Americans would actually do this.”

According to the New York Post, Mr Pompeo made the remarks after a successful trip to North Korea that resulted in him returning home last week with three freed American hostages.

He was in Pyongyang laying the groundwork for a meeting between Mr Trump and Kim next month.

The US wants the “complete verifiable, irreversible denuclearisation of North Korea,” Mr Pompeo said.

In return, the US would help the isolated regime economically prosper with private sector investment to build out the energy grid, infrastructure and agriculture, Mr Pompeo said.

Asked whether the US would also offer guarantees that Kim would stay in power, Mr Pompeo said there would “assurances,” but he did not elaborate.

“(Kim) appreciates the fact that this will have to be different and big and special and something that has never been undertaken before,” Mr Pompeo said. “If we’re going to get to this historic outcome both sides have to be prepared to take truly historic measures to achieve it.”

He added: “It is our fervent hope that Chairman Kim wants to make a strategic change … and if he’s prepared to do that then President Trump is prepared to assure that this could be a successful transition.”

Aside from former NBA basketball star Dennis Rodman, Mr Pompeo is one of the few Americans who has spent time with the North Korean leader.

“The conversations are professional. He knows his brief,” Mr Pompeo said, describing his meetings with Kim. “He is able to deal with complexity when the conversation requires it.”

The young North Korean leader also has an interest in the US media.

“He does follow the Western press. He’ll probably watch this show at some point,” Pompeo said. “He’s paying attention to things that the world is saying.”

The summit is set for June 12 in Singapore.