North Korea on its part blasted the United States for insisting it give up all its nuclear programmes without receiving any concessions first, saying on Friday it would persist in atomic development until it is given a nuclear reactor in exchange for abandoning weapons development.
Amidst this, the six-party talks in Beijing looked in jeopardy on Friday - their fourth day - as Pyongyang hung tough, rejecting a South Korean offer of electricity in return for renouncing nuclear arms and insisting on its right to nuclear energy.
But China, hosting the negotiations, put forward a revised draft statement which was thought to acknowledge North Korea's right in principle to an atomic-energy programme, offering a potential way out of the stalemate.
"We think that this new document is balanced in character, and it includes North Korea's right to peaceful atomic energy and the possibility in the long term of building a light-water nuclear reactor," Russian news agencies quoted Russian chief negotiator Alexander Alexeyev as saying.
China has asked all parties for a response on its draft by Saturday afternoon, a South Korean official said. Alexeyev said the talks would go into recess if no agreement was reached on the statement by that time.
US Secretary of State Condoleezza Rice said Washington wanted to see progress within five days and warned that the United States was not solely dependent on the talks to get North Korea to abandon its nuclear ambitions.
China's offer may acknowledge
the right to nuclear energy
"We're not sitting still, you know, we're working on anti-proliferation measures that help to protect us," Rice said in an interview conducted on Thursday with the New York Post, a transcript of which was released by the State Department.
"The president signed an executive order, if you remember that freezes assets and some entities that we believe that are engaging in proliferation trade," she said.
With the talks between the two Koreas, the US, Japan, Russia and China already deadlocked over North Korea's insistence on being supplied with a light-water nuclear reactor, reports said that Pyongyang had gone further and threatened to boost nuclear weapons production if its demand was not met.
South Korea has offered to supply the North with 2000 megawatts of electricity if it scraps its nuclear weapons programmes, and has said it would not be opposed in principle to Pyongyang having an atomic energy programme in the future.
But North Korea turned the offer down.
"If the United States keeps refusing to give light water reactors, the basic yardstick of trust, we will never be able to stop our own peaceful nuclear activities even for a moment," the spokesman for North Korea's delegation at six-party talks, Hyun Hak-bong, said.
"We will never accept the demand that we should give up our nuclear (deterrent first)"
North Korean spokesman
He called the US demand that North Korea give up its nuclear arsenal before receiving security guarantees and economic and energy aid "a naive demand".
"Our position is as follows: don't even dream about it," he said.
"We will never accept the demand that we should give up our nuclear (deterrent first)."
But Alexeyev said the Chinese draft proposal, which he said acknowledged North Korea's right to a light-water reactor in future, could be an acceptable compromise.
"In our view, this formula ... could satisfy all sides," he was quoted as saying.
Failure to reach an accord in Beijing could prompt Washington to take the issue to the UN Security Council and press for sanctions. China opposes such a move, and North Korea has said sanctions would be tantamount to war.
Rice hinted at a deadline for the negotiations.
"So we'll see, I think in the next five or so days ... whether or not they're prepared to make a strategic choice about their nuclear weapons programmes," she said.
Japan's chief negotiator, Kenichiro Sasae, said it was still too soon to say whether the deadlock could be broken. "I am neither optimistic nor pessimistic at this stage," he said.