Seoul's top diplomat said Wednesday that North Korea's human rights record is unlikely to be discussed at this month's summit, after Pyongyang denounced the South for supporting a fresh UN resolution against the North.
North Korean leader Kim Jong Un and the South's president Moon Jae-in are due to meet for a rare inter-Korean summit on April 27.
But Pyongyang's state media condemned South Korea Tuesday for its "dubious double dealing," after Seoul welcomed a new United Nations resolution against North Korea's human rights violations.
Such action could jeopardize future dialogue, the North warned.
"This is an open political provocation to the DPRK and an intolerable act of chilling the atmosphere for dialogue," the North's official KCNA agency said in a commentary, using North Korea's official acronyms.
It added: "Whom are they going to hold dialogue with and whom are they going to improve relations with while denying the dignity and social system of the dialogue partner?"
South Korea's foreign minister Kang Kyung-wha said Seoul maintains a "firm stance" against the "dire human rights situation" in the North but that the prospect of Moon discussing it with Kim this month was unlikely.
"In order to enhance dialogue, the topics that both sides have agreed upon will be discussed," Kang told reporters.
"So to include it in the agenda of South-North dialogue, I think the government will need more preparation," she said.
North Korea's rights record has been heavily criticised by the United States and the United Nations.
The North is estimated to have up to 120,000 political prisoners in its sprawling gulag system.
A U.N. commission published a searing report in 2014 which concluded North Korea was committing human rights violations "without parallel in the contemporary world."
The summit will be only the third of its kind since the 1950-53 Korean War ended with an armistice.
It comes amid a rapid diplomatic thaw on the peninsula that has seen Kim enjoy a K-pop concert by artists from the South in Pyongyang.
The two Koreas have yet to set an agenda for the summit, which will take place in the demilitarised zone.
Officials from both sides will meet Thursday for working-level talks to discuss issues including protocol and security.
Landmark talks between Kim and U.S. President Donald Trump are planned next month.