The letter appeared to be in response to a comment from Trump last Thursday when he canceled the summit, accusing Pyongyang of hostility, but urged the North Korean leader to "call me or write" if he had a change of heart.
Former U.S. officials who have negotiated with North Korea have cautioned that the Kim family regime has violated past deals aimed at curbing the nation's nuclear and ballistic missile programs. He and Pompeo had discussions over dinner of steak, corn and cheese on Wednesday (Thursday NZT), Pompeo said in a tweet. The senior North Korean's visit marks the highest-level official visit to the United States in 18 years.
Trump and Pompeo posed for several rounds of photos with the North Korean delegation before walking their visitor back his black Chevrolet Suburban at 2:40 pm.
Meanwhile, North and South Korean officials continue their dialogue on Friday at the border village of Panmunjom.
Sergei Lavrov was welcomed with open arms by Kim as he flew into the hermit kingdom in an apparent bid to curry favour ahead of the crucial summit between North Korea and the USA in Singapore next month.
Lavrov began his visit to North Korea by meeting with Foreign Minister Ri Yong Ho. I believe they will be coming down to Washington on Friday (Saturday NZT).
Trump says he didn't open the letter. "It is very important to them". "We talked about ending the war", Trump said. It is all a process.
China rejects 'ridiculous' U.S. accusation of South China Sea militarization
He said the government was merely looking for a "proper time" to take "full advantage" of the arbitral ruling. Mattis was heading to Hawaii to attend a change-of-command ceremony for the USA military's Pacific Command.
"If it happens, we'll certainly be ready", White House spokeswoman Sarah Huckabee Sanders said of the Singapore summit.
U.S. President Donald Trump and North Korean leader Kim Jung Un had been scheduled to hold an unprecedented summit in Singapore on June 12.
A man watches a television news screen showing US President Donald Trump, left, and North Korean leader Kim Jong Un, at a railway station in Seoul on May 25, 2018.
"We're meeting with the chairman on June 12 - and I think it's probably going to be a very successful", Trump said.
He wants North Korea to "denuclearise", meaning to get rid of its nuclear arms, in return for relief from economic sanctions but the leadership in Pyongyang is believed to regard nuclear weapons as crucial to its survival and has rejected unilaterally disarming.
The US side is pressing its demand for "complete, verifiable, irreversible denuclearization". Disputes between Washington and Pyongyang led Trump to cancel the meeting, only to see a renewal of diplomatic efforts in recent days.
As expected, Kim Yong Chol handed Trump a letter from Kim that may clear up some of the questions.