South Korean President Moon Jae-in has said it was "too early to be optimistic" about the North's offer to discuss denuclearization with the United States.
"We are only at the starting line," Moon told political party leaders on March 7 after his envoys revealed Kim Jong Un's offer following their return from a historic trip to Pyongyang.
Moon rejected allegations of a behind-the-scenes agreement with Pyongyang in return for it coming to the negotiating table.
"There will be no such a thing as a gift to the North," Moon added.
The South's leader reaffirmed the importance of maintaining close co-operation with the United States, its security guarantor, adding: "I think denuclearization talks will become feasible only when South Korea and the United States take common positions" on the issue.
Monn also said there would be no let-up in sanctions or pressure purely as a result of inter-Korean dialogue.
"Inter-Korean talks won't be enough to achieve peace," he said.
Earlier, U.S. President Donald Trump said that he believed North Korea's offer to hold denuclearization talks is "sincere."
"I think they're sincere also because of the sanctions and what we're doing with respect to North Korea," he told reporters on March 6.
The U.S. president had previously said that "the statements coming out of South Korea and North Korea have been very positive", but also said it might be a "false hope."
Meanwhile, Vice President Mike Pence said Washington would not alter its stance toward Pyongyang without "credible, verifiable, and concrete steps" toward denuclearization.
North Korea has yet to confirm details of the announcements from Seoul that appeared to open the door to dialogue between Washington and Pyongyang after months of insults and threats of war between Trump and Pyongyang.
Seoul also said that North Korea has agreed to hold a summit with the South in late April.
The rival Koreas have been taking steps to repair ties strained by North Korean nuclear weapons and missile tests after Pyongyang reached out to Seoul over the recently concluded Pyeongchang Olympics.