CIA director Mike Pompeo has defended Donald Trump's decision to meet North Korean leader Kim Jong-un, saying the president understands the risks.
Mr Trump "isn't doing this for theatre, he is going there to solve a problem," the spy chief told Fox News Sunday.
The president has said the summit could produce the "greatest deal for the world".
But critics have warned that if the talks go poorly, the two nations will be in a worse position than before.
No sitting US president has ever met a North Korean leader. Mr Trump reportedly accepted the offer to do so on the spot when it was relayed by South Korean envoys on Thursday, taking his own administration by surprise.
Attempts to negotiate aid-for-disarmament deals have failed repeatedly since 2003, when the North pulled out of the Nuclear Non-Proliferation Treaty (NPT).
Mr Pompeo told CBS the administration had its eyes "wide open" to the challenge of dealing with North Korea.
He said the country was coming to the table now because US-led sanctions have battered it economically.
"Never before have we had the North Koreans in a position where their economy was at such risk, where their leadership was under such pressure," he told Fox News.
Another top White House official, Treasury Secretary Steve Mnuchin, stressed the "clear" objective of the talks was getting rid of nuclear weapons on the Korean peninsula, and restated that the US expects there to be no missile or nuclear test ahead of the meeting.