North Korea asks for formal end to war

North Korea has proposed a peace treaty to formally end the Korean War, a move seen as an attempt to bolster its position ahead of any denuclearisation talks.

But the White House made clear that North Korea must first resume long-stalled six-country nuclear negotiations, and the Obama administration's newly appointed point man for human rights in North Korea said ties can only improve once Pyongyang ends its systemic abuse of its citizens.

North Korea said a few weeks ago it was ready to end its year-long boycott of six-country nuclear talks, but analysts said the North may try to attach conditions to its return to the discussions among the two Koreas, China, Japan, Russia and the United States.

"If confidence is to be built between the DPRK (North Korea) and the U.S., it is essential to conclude a peace treaty for terminating the state of war, a root cause of the hostile relations, to begin with," the North's KCNA news agency quoted a Foreign Ministry spokesman as saying.

"The removal of the barrier of such discrimination and distrust as sanctions may soon lead to the opening of the six-party talks."

The administrations of presidents Barack Obama and George W. Bush have said Washington can discuss a peace treaty once the North ends its nuclear arms programme, considered one of the biggest security risks to economically vital North Asia.

"The North Koreans are well aware of what they need to do to come back to ... six-party talks," White House spokesman Robert Gibbs told reporters, reiterating the U.S. position. "This isn't a step for us to take - this is a step for the North Koreans to take ... in living up to those obligations."