"Our policy hasn't changed and as the president stated, we have sanctions on, they're very powerful and we would not take those sanctions off unless North Korea denuclearized", she said. Also, given Trump's evident eagerness for the summit, he probably also sees an opportunity to reduce or eliminate USA forces in South Korea.
The talks, which were cancelled by Mr Trump before being re-scheduled last week for the same day and place, are expected to focus on Pyongyang's nuclear weapons program and tensions between the U.S. and North Korea.
COULD Dennis Rodman be key to ending North Korea's nuclear program?
Trump suggested on Friday that the most tangible outcome of the June 12 summit could be the "signing of a document" to end the technical state of hostilities - 65 years after the Korean conflict ended with an armistice, not a peace treaty.More news: Tim Cook reveals his tech habits: I use my phone too much
The June summit in Singapore will be an historic one, marking the first meeting between a North Korean leader and a sitting USA president.
US and North Korean officials are continuing to lay the groundwork ahead of the summit. Prince said that although it "seemed like everyone [in the U.S.] turned on" his client after he first visited North Korea, "now things seem to be happening, so he's just happy it's happening". South Korean intelligence has been unable to ascertain the fate of his predecessor, Pak Yong-sik, The Korea Herald reported.
Sanders told reporters on Monday in Washington that the summit would start on the morning of June 12. Despite all the ridicule he heaped on the Obama administration's Iran nuclear agreement, Trump may be discovering what veteran negotiators have known all along: It's hard to get a sovereign country, however vile its system, to give up a military capability it sees as essential to its security.
Ms Sanders said that the White House "advance team" - which features military, security, technical and medical staff - were already on the ground in Singapore.More news: Breakthrough with new prostate cancer immune system drug
North Korean leader Kim Jong Un watches a basketball game between former US NBA basketball players and North Korean players, with Dennis Rodman at Pyongyang Indoor Stadium in Pyongyang January 9, 2014.
Not far from there is the Shangri-La Hotel, the site for the historic and only meeting between China's President Xi Jinping and then-Taiwan leader Ma Ying-jeou in 2015.
Donald Trump has clearly spelt out that he wants to denuclearise North Korea.
For instance, Moon's predecessor Park Geun-hye's decision to let the United States deploy THAAD was made at the bilateral level.More news: Job listings point to new Diablo game
"I think what Mr.Abe expects is (that Trump) will at least raise this issue with Kim Jong Un when they meet", said Tetsuo Kotani, a senior fellow at the Japan Institute of International Affairs.