Pompeo, who has met Kim in Pyongyang twice in recent weeks to prepare the groundwork for a summit with President Donald Trump, told the House Foreign Affairs Committee that the historic talks are "still scheduled for June 12" despite reports of differences between the two sides.

"We're optimistic that we can achieve an outcome that would be great for the world," Pompeo said.

In their most recent meeting two weeks ago, Pompeo said he and Kim talked about their mutual goals for the talks.

"We still have a lots of work to do to find common ground," Pompeo said.

But Kim "has shared candidly that he understands that economic growth for his people, the well-being of his people, depends on a strategic shift."

Pompeo said he made clear to Kim the US view of what steps Pyongyang needs to take, including verification work, in order to demonstrate "real denuclearization."

"He made clear it was important to him that when that time came, when those objectives had been achieved, he in turn would receive economic help from America in the form of private sector business's knowledge and know-how," Pompeo said.

Pompeo said Kim also "wanted security assurances from the world, the end of the status that sits between South and North Korea, with the eventual goal of a peace treaty."

Pompeo declined to answer a lawmaker's question on whether the Pentagon had dialed back its military drills with South Korea to assuage Kim's concerns.

But he added: "It is my view that we have made zero concessions to Chairman Kim to date and we have no intention of doing so."