North Korea is reportedly advocating for the summit to be in Pyongyang, while the capital of Mongolia is also under consideration.
Officials said the current target is late May or even June, according to CNN.
"Even if we were aware of the talks, we can not comment on it", said an anonymous Cheong Wad Dae official, according to Yonhap News Agency.
South Korea had conveyed a message from Kim indicating his willingness to pause his nuclear program during talks, but the USA had not previously confirmed Kim's intentions directly from North Korea.
"The US has confirmed that Kim Jong Un is willing to discuss the denuclearization of the Korean Peninsula", a Trump administration official told The Wall Street Journal and Washington Post on Sunday. American and North Korean intelligence officials have spoken several times and have even met in a third country, with a focus on nailing down a location for the talks, CNN reported.
The back-channel talks are the latest move in a flurry of diplomatic activity aimed at resolving the nuclear crisis on the Korean peninsula.
Kim will meet with his South Korean counterpart, Moon Jae-in, at the border truce village of Panmunjom on 27 April.More news: Russian GP wants to bring back 'grid girls' for race in September
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South Korea's National Intelligence Service Chief Suh Hoon has been in close contact with his United States and North Korean counterparts, reported Korea Herald.
The North Koreans want the meeting to take place in their capital, Pyongyang.
"It's a natural step in the right direction".
US and North Korean officials have reportedly been trying to nail down a location for the summit, with the North Koreans pushing for Pyongyang and the Americans calling for a more neutral location, like Ulaanbaatar in Mongolia.
"But we can not say for certain that the U.S. counterpart in the North was Reconnaissance General Bureau".
She added, "But we're going into this very cautiously, very much knowing that he's looked at the Iran deal, he's seen what he can get and he's seen how he can push through loopholes, and we're not going to let that happen again".
The Koreas earlier this week held separate working-level discussions on the protocol, security and media coverage issues of the inter-Korean summit.