Seol: North Korea on Saturday took further steps to mend ties with South Korea, suggesting talks be held within weeks and reopening an office to foster cooperation on the fractured peninsula.

The latest offer from Pyongyang follows an apparent easing in tensions, which have soared since the North shelled the South's frontline Yeonpyeong island on November 23, killing four people.

Pyongyang's Committee for the Peaceful Reunification of the Fatherland 'formally' proposed an 'unconditional and early opening' of talks between the two governments.

"The level of the talks and their venue and the date of their opening may be decided under a bilateral agreement," it said.

The committee, the official agency in charge of inter-Korean exchanges, said in its statement that there is 'neither conditionality in the North's proposal for dialogue nor need to cast any doubt about its real intention.'

"The South Korean authorities should discard any unnecessary misgiving, open their hearts and positively respond to the North's proposal," the statement said.

South Korea said the latest offer, which comes after Beijing said it would 'support and welcome' any dialogue between the North and South, was more concrete than a suggestion for 'early and unconditional' talks earlier in the week announced through Pyongyang media.

"The government is now analysing the background and intention of this overture," Unification Ministry spokeswoman Lee Jong-Joo said.

North Korea also proposed an early resumption of talks between the two nations' Red Cross organisations on humanitarian issues and other negotiations aimed at reviving economic exchanges and cross-border tours.

South Korea in May last year suspended almost all cross-border economic exchanges, putting the blame on the North for the sinking of a South Korean warship in March, an allegation angrily denied by Pyongyang.

North Korea responded by closing the office in its Kaesong City near the border which was used to facilitate inter-Korean economic cooperation but said on Saturday it would now re-open the office as a 'measure of good faith'.

Talks on a range of issues, including the resumption of tours of the North's scenic Mount Kumgang and a joint industrial asset at Kaesong should be restarted at an early date, it said.

"We also propose that Kaesong be their venues and they take place at the end of January or in the first half of February," the North said.

Professor Kim Yong-Hyun of Dongguk University said Saturday's overture came in response to the demand from China and the United States that inter-Korean relations should be improved before six-party disarmament talks can be resumed.

"In addition, the North is seeking to obtain economic gains through the resumption of inter-Korean economic exchanges and to stabilise a third generation succession scheme," he said.

Kim Jong-Il, 68, who took over from his own father, Kim Il-Sung, is known to be accelerating the transfer of power to his son Jong-Un after suffering a stroke in 2008.

The North quit the six-nation talks, which group the two Koreas, Japan, China, Russia and the US, in April 2009 and staged a nuclear test a month later, its second since 2006, in protest at continuing 'hostile' US policy toward the communist state.

Relations between the two Koreas were stretched to breaking point after the North's shelling in November, which killed four people including two civilians.

But after a difficult year on the Korean peninsula, 2011 started on a more peaceful note.

The North began the year calling for improved relations with Seoul, while South Korean President Lee Myung-Bak Monday also reached out, saying he was open to talks and offering closer economic ties.