South Korean President Moon Jae-in and North Korean leader Kim Jong un are also set to meet next week. "He will likely take this shift in tone as an encouraging sign", Mount said of the apparent dropped USA troop withdrawal demand and other modifications the North has made to its stance.
And what did representatives for the two long-estranged capitals talk about?
He also asked Catholics to check the "hostile" attitude that has crept into Korean society since the end of the Korean War. None of them are in the US. "That's the thing to be concerned about over time".
"Just because North Korea is responding to dialogue, there should be no reward".
Trump has frequently invoked the case of college student Otto Warmbier, who died last summer a few days after being released from the North in a coma after 17 months in captivity.
This week it emerged that CIA Director Mike Pompeo, Trump's nominee for secretary of state, traveled to the North Korean capital for secret, preliminary talks ahead of the Trump-Kim meeting, which is set for late May or early June. Asked on Wednesday whether he would cancel the planned meeting if there were no assurances that he detainees would be freed, Trump did not answer directly. "And I appreciate that very much", he said.
Lee is also likely to meet Susan Thornton, acting U.S. assistant secretary of state for East Asian and Pacific Affairs. Tokyo says at least a dozen Japanese said to have been taken in the 1970s and 1980s remain unaccounted for.
"From April 21, North Korea will stop nuclear tests and launches of intercontinental ballistic missiles", the Korean Central News Agency said, according to Yonhap News.
Moon and Kim plan to make their first telephone conversation sometime before their face-to-face meeting.
Sanctions, however, wrote Delury, "keep Kim from achieving his ultimate ambition - what he wants at least as ardently as a nuclear deterrent - making North Korea a wealthy country".
In many regards, a first-ever summit between a sitting US president and a North Korean leader is perfectly suited to the ego of Trump, who thrilled supporters during the Republican National Convention in July 2016 when he declared, "I alone can fix it". During a meeting with Trump, Abe scored a major win when Trump promised he'd bring up the issue during the upcoming historic meeting with Kim.
Inter-Korean relations have been improving since the North chose to take part in the February 9-25 Pyeongchang Winter Olympics hosted by South Korea.
It would obviously be a real concern to Japan that in the context of a new regional security arrangement the U.S. may decide to scale down its military presence in Japan.
Kim, for his part, could agree to an indefinite cessation of nuclear and missile tests.
Therefore, any genuine long-term progress with North Korea will require tough, detailed and likely months- or years-long diplomacy. Such a move could open the door more humanitarian or economic aid to Pyongyang.
North Korea also vowed to actively engage with regional neighbors and the global community to secure peace in the Korean Peninsula and create an "optimal worldwide environment" to build its economy.