The report says a North Korean torpedo fired from a submarine sank the ship.
“There is no ground whatsoever for the south side to refuse to receive the inspection group of the NDC (National Defence Commission) if the results of the investigation are objective and scientific as claimed by the south side,” North Korean Defence Minister Kim Yong-Chun said in a message sent to the South.
A report released on Thursday had concluded that the evidence was “overwhelming” with “no other plausible explanation” for the sinking of the 1,200 tonne Cheonan vessel.
The North quickly responded claiming the report was “sheer fabrication”. While some analysts are not sure this offers “100 per cent perfect proof”.
Noh Jong Sun from Yonsei University in Seoul told RFI that radar would have picked up something, although “there is no evidence of detecting this torpedo approaching this ship”.
He also points out that this area is under heavy surveillance.
“There is satellite right on the spot of this demilitarised zone - there is no indication about this approaching torpedo.”
There are questions about the authenticity of the torpedo’s markings.
“There are two letters,” says the political analyst, but they have been added “by handwriting with ink”.
On Friday South Korea insisted that the North should attend US-led United Nations Command talks. They are currently determining the scope of the alleged armistice violation related to the sinking.
The North’s defence minister said on Saturday that the UNC had no authority to intervene. He said issues of territorial waters must be resolved by the two countries’ military.
During US Secretary of State Hillary Clinton's visit to China she urged the North to accept the report.
"We'd like to see them acknowledge the reality of what happened and then join with South Korea, Japan and us in helping to fashion a response that helps to change North Korean behaviour," a senior official travelling with Clinton said on Friday.
The official said that Clinton would try to make a strong case to China, who's support is seen as necessary for any international action.