For his part, Sanders, a presidential contender in the 2016 election, said that he is "very anxious about North Korea's nuclear capability" and seemed skeptical that Trump is taking diplomacy seriously. "Being a retired admiral, he [Song] is quick to suggest what I should do with the naval forces assigned to me", Swift said.
January 1, 2018: Kim says in his New Year's address that he has a nuclear button on his desk, but also calls for improved relations with South Korea and suggests sending a delegation to the Winter Olympics in Pyeongchang, South Korea.
South Korea's national security adviser, Chung Eui-yong, who delivered the invitation to Trump in Washington after a visit by his delegation to Pyongyang earlier this week, was careful to praise Trump's influence over the developments.
But in an interview that aired April 30, he called Kim "a pretty smart cookie" - expressing admiration that the North Korean strongman "was able to assume power" at a young age.
"A small step to peace that started out as a joint inter-Korean women's ice hockey team has been growing rapidly like a snowball", he said. "In the meantime, all sanctions and maximum pressure must remain".
Trump jumped on his favored medium of Twitter in response: "North Korean Leader Kim Jong Un just stated that the 'Nuclear Button is on his desk at all times.' Will someone from his depleted and food starved regime please inform him that I too have a Nuclear Button, but it is a much bigger & more powerful one than his, and my Button works!"
The head of South Korea's National Security Office, Chung Eui-yong, speaking in Washington on Thursday after briefing Trump about a meeting South Korean officials held with Kim this week, said the US president had agreed to meet the North Korean leader by May in response to an invitation from Kim.
The reaction has been muted because gold had failed to show strong safe-haven demand a year ago during months of insults exchanged over the North's nuclear and missile programmes, he added.
US President Donald Trump told supporters at the Make America Great Again Rally in Pennsylvania that North Korea's leaders"want to make peace
July 28: A second Hwasong-14 is launched with an estimated range reaching into the USA mainland, including cities such as Chicago.
Jeffrey Lewis, who heads the respected East Asia Nonproliferation Program at the Middlebury Institute of Strategic Studies, said Trump was dancing to Kim s tune.
A commentary in China's official Xinhua news agency said that a Trump-Kim meeting would show "notable progress regarding the Korean Peninsula nuclear issue, and deserves applause from everyone, especially after the tit-for-tat vicious cycle as Washington and Pyongyang repeatedly traded threats that raised the specter of a nuclear war in the region previous year".
September 22: Kim accuses Trump of "mentally deranged behavior".
In his debut speech at the United Nations in September, Trump dubbed Kim a "rocket man" on a "suicide mission".
Russia: Foreign Minister Sergei Lavrov hailed the proposed meeting as "a step in the right direction".
Sanders' words on Friday also marked the White House's first comments preconditioning the meeting. "Hopefully, the agreement will be implemented", he said, while on a trip to Ethiopia.