US President Donald Trump has said he would be "honoured" to meet North Korean leader Kim Jong-un, in the right circumstances.
"If it would be appropriate for me to meet with him, I would - absolutely. I would be honoured to do it," he told news organisation Bloomberg on Monday.
The previous day he described Mr Kim as a "pretty smart cookie".
The comments come amid escalating tensions over North Korea's nuclear programme.
The White House issued a statement following Mr Trump's remarks, saying North Korea would need to meet many conditions before any meeting between the two leaders could take place.
Spokesman Sean Spicer said Washington wanted to see the North end its provocative behaviour immediately.
"Clearly conditions are not there right now," he added.
In Sunday's interview with CBS, President Trump noted Mr Kim had assumed power at a young age, despite dealing with "some very tough people".
He said he had "no idea" whether Mr Kim was sane.
The North Korean leader had his uncle executed two years after he came to power, and is suspected of ordering the recent killing of his half-brother.
President Trump, asked what he made of the North Korean leader, told CBS: "People are saying: 'Is he sane?' I have no idea... but he was a young man of 26 or 27... when his father died. He's dealing with obviously very tough people, in particular the generals and others.
"And at a very young age, he was able to assume power. A lot of people, I'm sure, tried to take that power away, whether it was his uncle or anybody else. And he was able to do it. So obviously, he's a pretty smart cookie."
On Saturday North Korea conducted its second failed ballistic missile test in two weeks.
Tensions in the region have increased lately, with both North and South Korea conducting military exercises.
The US sent warships to the region and began installing a controversial anti-missile system in South Korea last week.
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On Sunday, an article from Pyongyang's state-run news agency KCNA urged the US to "ponder over the catastrophic consequences to be entailed by their foolish military provocation".
North Korea has carried out repeated missile tests in recent months and is threatening to conduct its sixth nuclear test.
President Trump told CBS the US was "not going to be very happy" if further tests were carried out. When asked whether this would mean military action he said: "I don't know. I mean, we'll see."