"We had hundreds of new sanctions ready to go", he said, but that they wouldn't be imposed "until the talks break down".
Pompeo said they finished everything they needed to address in the morning session.
Washington is determined that Kim should agree to what U.S. officials call the "complete, verifiable and irreversible" end of North Korea's nuclear weapons and intercontinental missile programs. Trump suddenly withdrew from the meeting last week, only to announce a day later that it could still get back on track.
There is speculation that Kim Yong-chol could visit Washington and meet with Trump.
"I look forward to the day I can take the sanctions off North Korea", Trump said.
"I think it's probably going to be a very successful, ultimately a successful process", Trump told reporters on the White House lawn after meeting with a senior North Korean official in the Oval Office.
Trump later told the Reuters news agency it may take more than one meeting with Kim Jong Un to seal a denuclearization deal with North Korea and that he would like Pyongyang to dismantle its nuclear weapons program as quickly as possible under any agreement. "We welcome the summits that already took place between Pyongyang and Seoul as well as planned meetings between North Korean and USA leadership".
"You people are going to have to travel, because you'll be in Singapore on June 12th", he told reporters awaiting word of the meeting. The big thing will be on June 12.
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They believe it's the same group that hacked the Democratic National Committee before the presidential election in 2016. USA law enforcement officials have already acted to help disrupt the VPNFilter malware and its associated botnet.
Trump made the announcement on Friday after welcoming Kim Jong-un's right-hand man, Kim Yong-chol, to the White House to talk about Washington's demands of de-nuclearisation in the Korean peninsula.
Trump says he didn't open the letter.
But pressed further about the content of the letter, Mr. Trump admitted he hasn't opened the letter yet, and said he could be in for a "surprise". "The United States continues to actively prepare for President Trump's expected summit with leader Kim in Singapore".
Kim's right hand man General Kim Yong Chol flew into NY on Wednesday to discuss preparations for the assembly.
They met for 45 minutes and Jo brought Clinton a letter from Kim, the father of North Korea's current leader. He is North Korea's former military intelligence chief and is one of the North Korean leader's closest aides.
The letter comes as the two countries work to revive a Trump-Kim summit on June 12 in Singapore. The senior North Korean's visit marks the highest-level official visit to the United States in 18 years.
After receiving a "personal letter" from Putin, which was delivered by Lavrov, Kim expressed hope to promote "high-level" talks in order to "continue to develop strategic and traditional relations" between Russian Federation and North Korea.
Mr. Clinton's secretary of state, Madeleine Albright, later visited the North Korean capital, but the negotiating effort eventually collapsed.