North Korea's envoy to disarmament talks in Beijing says Pyongyang has the right to operate nuclear programmes for peaceful purposes.
Mr Kim said the North wants to retain "peaceful nuclear activities"
Delegates say the demand has deadlocked work on a statement of principles for negotiations, aimed at persuading the North to give up its nuclear programme.
In return, Pyongyang wants aid and security guarantees.
But the US has always insisted that North Korea abandon its nuclear ambitions before concessions are made.
China said diplomats would meet again on Friday for an 11th day of talks.
The North Korean envoy, Vice-Minister of Foreign Affairs Kim Kye-gwan, said that delegates were "at a stalemate" in work on the statement of principles.
Oct 2002: US says North Korea is enriching uranium in violation of agreements
Dec 2002: North Korea removes UN seals from Yongbyon nuclear reactor, expels inspectors
Feb 2003: IAEA refers North Korea to UN Security Council
Aug 2003: First round of six-nation talks begins in Beijing
Feb 2005: Pyongyang says it has built nuclear weapons for self-defence
"We are for denuclearising, but we also want to possess the right to peaceful nuclear activities," Mr Kim said outside the talks, the Associated Press news agency reported.
Only the US opposed allowing Pyongyang a right enjoyed by other countries, he added.
Three previous rounds of talks have ended in failure.
US negotiator Christopher Hill said the US had done "everything we can do" during the Beijing talks.
He urged the North to sign the statement put forward by China and backed by four of the other nations involved in six-party talks with North Korea - the US, South Korea, Japan and Russia.
The two-page draft is seen as the last-ditch attempt to save the open-ended talks.
Both Mr Hill and Mr Kim have expressed doubts that an agreement can be achieved.
However, earlier on Thursday, Mr Hill had said that the latest draft - sent overnight to all the teams - appeared to be getting "to the point where we can agree something".
Mr Hill said there needed to be clear principles for disarmament talks
He also suggested that the talks were approaching the final stages of discussions.
Japanese chief negotiator Kenichiro Sasae agreed that the negotiations "had come to a crucial stage".
According to South Korea's chief delegate Song Min-soon, the new draft contains statements on energy aid for North Korea, normalisation of relations with the US and Japan, and the provision of peaceful nuclear energy for the North.
The crisis first erupted in 2002 when the United States accused North Korea of pursuing an uranium enrichment project to make nuclear weapons.
The stand-off deepened when Pyongyang withdrew from the Non-Proliferation Treaty (NPT) and announced earlier this year that it had plutonium-based nuclear weapons.
It continues to deny any uranium-based capability.