The previous U.S. stance, said Bruce Klingner of the Heritage Foundation, was that "we don't deploy a president to negotiate a treaty, we deploy a president to sign a treaty where we know where every piece of punctuation is on that piece of paper".
He and Trump are set to meet Tuesday morning in the first summit of its kind between a leader of North Korea and a sitting USA president.
Kim and Trump arrived in tropical Singapore on Sunday for the first ever face-to-face meeting by leaders of two countries that have been enemies since the 1950-1953 Korean War.
Chairman Kim yesterday held a meeting with Prime Minister Lee. Earlier this month, Singapore's defense minister said the US trade threats were as disruptive to the global order as China's military deployments in the disputed South China Sea.
Lobster bisque, beef tenderloin and ice cream were on the lunch menu, and there was also an early birthday cake for Trump, who turns 72 on Thursday.
The North Korean autocrat's every move will be followed by 3,000 journalists who have converged on Singapore, and by gawkers around the world, up until he shakes hands with Trump on Tuesday.
Federal Reserve raises United States interest rates again
The move reflects the economy's resilience, the job market's strength and inflation that's finally nearing the Fed's target level. The unemployment rate is seen falling to 3.6 percent in 2018, compared to the 3.8 percent forecast in March.
According to Kyodo news agency, depending on the outcome of the negotiations in Singapore and possible summit in Pyongyang, a third round of talks may take place in Washington in September.
He thanked Singapore's organisation of the summit as if it was "their own family affair". Others complained about the traffic jams in downtown Singapore.
An aviation source in China said, "It probably cost a lot of money as well as representing a huge political burden to loan Kim the aircraft".
"It is our contribution to an global endeavour which is in our profound interest", he told reporters on Sunday.
Trump and Kim are staying in separate hotels in the famous Orchard Road area of Singapore, dotted with high-rise luxury apartment blocks, offices and glittering shopping malls.
It formally referred to Trump by his full name in the Monday report, including his middle initial - the first time it has done so. It heralded the summit as part of a "changed era".
Discussions would focus on "the issue of building a permanent and durable peace-keeping mechanism on the Korean peninsula, the issue of realising the denuclearisation of the Korean peninsula and other issues of mutual concern", KCNA said.