President Lee Myung-bak is said to favour a tough line with Pyongyang
South Korea is reported to be planning to challenge North Korea on its human rights record, indicating a harder line from Seoul's new government.
Reports quoting unnamed officials say the South is set to vote for a draft UN resolution expressing deep concern over the rights violations in the North.
The South has frequently abstained from such votes, fearful of souring relations with its communist neighbour.
The UN Human Rights Council in Geneva will consider the resolution this week.
The South Korean newspaper Chosun Ilbo quoted an official as saying the new government, which took charge in February, regards human rights as "a universal value".
"The government will show the first example of concrete action in the upcoming UNHRC vote," the official said.
The resolution expresses deep concern at what it says are continuing reports of systematic, widespread and grave violations of human rights in the North.
In the past five years, the South has voted for only one such resolution - in 2006 after Pyongyang's test of a nuclear weapon.
The BBC's John Sudworth, in Seoul, says successive liberal governments have taken a careful line with Pyongyang.
They have feared that harsh criticism might upset the efforts for closer engagement between the old enemies, our correspondent adds.
Analysts say the approval of the UN resolution would be the first sign that new conservative President Lee Myung-bak is prepared to take a tougher stance towards the North.