CNN on Saturday quoted multiple government officials familiar with the discussions as saying that the talks are a sign that planning for the highly anticipated meeting is progressing.
US and North Korean officials have held secret contacts recently in which Pyongyang directly confirmed its willingness to hold the unprecedented summit, the official told Reuters, speaking on condition of anonymity.
The North Koreans are pushing to have the meeting in their capital, Pyongyang, the sources said, although it is unclear whether the White House would be willing to hold the talks there. The Koreas agreed on the date of the summit in a high-level meeting last week.
As recently as this weekend, Trump told associates he was looking forward to the summit, which he agreed to on the spot when presented the invitation from Kim. "It's a good signal that the talks are going back and forth (between the USA and North Korea)".
USA officials were anxious South Korea may have hyped up Kim's openness to putting a denuclearization plan on the table. Officials said the current target is late May or even June.More news: Ford recalls 350000 vehicles: Some 2018 F-150s, Expeditions included
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The U.S. State Department has been communicating with the North Koreans through their mission at the United Nations, CNN also said.
Later this month (April), Kim and South Korean President Moon Jae In are to hold what would be the three inter-Korean summit.
Working-level officials need to determine how Kim would arrive at the southern side of the border village for the summit.
Lt.Gen. Benjamin C. Freakley told Arizona State University (ASU): "It's in the best interests of the United States and the rest of the world to be engaged in a diplomatic and political dialogue with the leadership of North Korea to try to prevent a nuclear or even a conventional war because they have an extremely sizeable military force".
North Korea was "suffocating" under global sanctions, Nikki Haley, the U.S. ambassador to the United Nations, said on Thursday, adding, "They need an out".