The officials told the Times that the President is becoming concerned that the meeting with North Korean leader Kim Jong Un "could turn into a political embarrassment" if negotiations to rid the North of its nuclear capabilities fall through and that he "has begun pressing his aides and allies" as to whether he should proceed.
Bolton is widely perceived to have a penchant for military action, as illustrated in a column he wrote for the Wall Street Journal in February laying out the legal arguments for strikes on North Korea.
The anticipated meeting between President Trump and North Korean dictator Kim Jong Un could put the former real estate tycoon eye to eye with a reviled autocrat who appears more in line with global thinking on one issue: climate change. Trump has said repeatedly he might pull out, and that scenario became more likely last week as the two governments traded heated words.
White House officials have told CNN that the Trump Administration has seen increased skepticism that the proposed summit between the USA and North Korean governments will go anywhere.
China faces a hard balancing act.
There is real doubt as to whether that would be a beneficial deal from the American perspective; it would certainly be worse than the Iran deal, which did not require USA concessions outside the nuclear arena.
Ahead of the unprecedented summit, Xi has inserted himself into the discussion.
It would be good if Moon, who in effect brokered the planned meeting between Trump and Kim, is able to continue to mediate between the two leaders.
China is North Korea's main trade partner, accounting for approximately 90 percent of trade with the rogue state, and its cooperation in enforcing economic sanctions is considered key to pressuring the country into an agreement.More news: Donald Tusk Lambasts Trump on Trade Decision, Iran Nuclear Deal
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Sen. Lindsey Graham (R-S.C.), also appearing on "Face the Nation" a week ago, said that exchanging aid for a denuclearized North Korea would be the "best money we ever spent".
Internationally, there are high hopes that China will play a positive role.
North Korea also bashed the Trump administration's comparison of North Korea, a country believed to be in possession of a functional nuclear arsenal, to Libya, a country which forfeited its nuclear program in the early stages of nuclear development. China had been increasing its purchases of North Korean coal in recent years.
North Korea had also carried out flight tests of three intercontinental ballistic missiles.
North Korea, judging from its recent statements, appears to perceive itself as a country that against all odds, including unbelievable worldwide pressure, emerged as a nuclear-armed country, and it is pushing the rest of the world to view it the same way.
Either way, many in South Korea are anxious about what happens if the Singapore summit fails to meet expectations - or if it produces a denuclearization deal North Korea fails to adhere to.
"It can't ensure compliance from either side", Kovrig said.
"It would be a great mistake for Kim Jong Un to think he could play Donald Trump", Pence said according to excerpts of an interview made available by Fox.
"My view is that this is less an issue of [North Korean] disinterest and more an issue of the deals themselves", said Richard Nephew, a senior research scholar at the Center on Global Energy Policy at Columbia University's School of worldwide and Public Affairs. Both the U.S. Geological Survey and the China Earthquake Networks Center described the second event as a possible "collapse" of the site.