Trump praises Kim Jong Un, saying he received a 'beautiful' letter from him

US President Donald Trump speaks to reporters before departing for a trip to Iowa. Photo / AP

US President Donald Trump said he received a "beautiful letter" from North Korean leader Kim Jong Un, a note he said portended progress for his Administration's stalled denuclearisation talks with the rogue regime.

Trump, speaking to reporters outside the White House today, said Kim's letter came yesterday.

"I can't show you the letter obviously, but it was a very personal, very warm, very nice letter," Trump said.

"North Korea has tremendous potential, and he'll be there. Under his leadership . . . And the one that feels that more than anybody is [Kim]. He gets it. He totally gets it."

Following Trump's summit with Kim in Vietnam that concluded in February without an agreement, North Korea has launched short-range missiles and halted negotiations with American diplomats. The regime has demanded that the United States drop its refusal to loosen sanctions until North Korea fully denuclearises.

But Trump touted the letter as a sign that the talks were on track. "I think that something will happen that's going to be very positive," he said.

Pete Buttigieg, one of Trump's would-be opponents in the 2020 presidential campaign had a prescient moment today when he told a crowd an hour before Trump spoke: "You will not see me exchanging love letters on White House letterhead with a brutal dictator who starves and murders his own people."

Trump also claimed that remains of US soldiers "keep coming back," but in reality, the Pentagon has suspended its efforts to recover those bodies.

The US military said it has been unable to reach North Korean officials to discuss issues related to the recovery of the remains.

"We have reached the point where we can no longer effectively plan, coordinate, and conduct field operations in the DPRK during this fiscal year, which ends on September 30, 2019," said the Defence Department agency in charge of recovering the remains.

Trump was also asked about the news that Kim's assassinated half brother was a CIA asset. The President said he'd tell Kim, "I wouldn't let that happen under my auspices."

It wasn't immediately clear if Trump meant that Kim wouldn't have killed his half brother under his tenure, or if Trump wouldn't have allowed Kim's half brother to become a CIA asset.