The remark was just a single sentence in a speech by a South Korean diplomat at a meeting of the UN Human Rights Council in Geneva on Monday. But it represented a major change after a decade in which South Korea largely refrained from criticism of its nuclear neighbour, fearful of upsetting reconciliation efforts.

The South Korean government 'calls upon the Democratic People's Republic of Korea to take appropriate measures to address the international community's concern that the human rights situation in the DPRK has not improved,' Mr Park In-kook, Seoul's deputy foreign minister in charge of international organizations and global issues, said in the speech. He referred to North Korea by its formal name.

North Korea struck back the next day, saying Pyongyang had 'strong doubt' whether the South remained committed to agreements between the two Koreas from summits in 2000 and 2007.

'South Korea must be held responsible for all the consequences arising out of these irresponsible remarks, which will have negative repercussions on the inter-Korean relations,' said Choe Myung Nam, a counselor at the North's diplomatic mission in Geneva.

The statement in Geneva was welcomed by human rights observers.

Ms Kay Seok, Seoul-based researcher for Human Rights Watch, praised the new government's stance and said she hoped it would continue to press the North for change.

The two Koreas have remained technically at war since 1953, when their three-year conflict ended in an armistice that has never been replaced by a peace treaty.

In the decades that followed, the rivalry was bitter and deadly.

North Korea tried several times to assassinate South Korean leaders.

Propaganda blared from loudspeakers across the no man's land dividing the peninsula, which is patrolled by hundreds of thousands of troops.

But the animosity softened in the late 1990s under the liberal government of Mr Kim Dae-jung, who won a Nobel Peace Prize in 2000 for staging the first summit between the Koreas. His successor, Mr Roh Moo-hyun, followed the same line and met North Korean leader Kim Jong Il in October.

But since conservative President Lee Myung-bak took office last week, cooler winds already have started to blow - with the South Korean statement in Geneva the most prominent sign so far.

Mr Lee had wanted to close the Unification Ministry, the main agency handling policy on North Korea that is often criticized by conservatives as too willing to coddle Pyongyang. He was forced to back down in the face of liberal parliament opposition.

Before his Feb 25 inauguration, Mr Lee also spurned a North Korean offer for talks between officials from both countries, a news report said Wednesday. The North backed off after Mr Lee demanded to know what the meeting would be about, the Dong-a Ilbo newspaper reported.

Sports dispute
Even in the realm of sports, the two sides are locked in a dispute over a World Cup qualifying match scheduled this month in Pyongyang, where the North has refused to allow the South Koreans to play their national anthem or fly their country's flag. Seoul says that would violate rules set by international soccer body Fifa, and has asked it to mediate.

The moves show South Korea is no longer treating the North as a special case like it previously did, said Mr Michael Breen, a longtime Korea watcher and author of 'The Koreans.' 'This government sees the North Korea issue as a foreign policy issue - and not even the most important one,' he said.

That stance can be expected to provoke a snubbed North Korea to seek ways of getting attention, Mr Breen said. For example, he said Pyongyang could create difficulties at joint tourism or business projects between the Koreas, or even spark small clashes along the countries' borders.

'I think we should brace ourselves because North Korea doesn't like to be ignored,' Mr Breen said. -- AP