WASHINGTON: The United States on Tuesday denied its envoys were heading to North Korea but said it was ready to talk to Pyongyang once it agreed to return to six-nation disarmament talks.

South Korean media reports said the reclusive state had issued invitations to the two US pointmen on North Korea -- Stephen Bosworth and Sung Kim -- in a bid to break months of soaring tension.

"We have no plans -- Ambassador Bosworth has no plans, Ambassador Kim has no plans -- to go to North Korea," State Department spokesman Ian Kelly told reporters.

Kelly refused to confirm or deny that North Korea issued an invitation.

"We are aware via these press reports that they would like to have Ambassador Bosworth and Ambassador Kim," Kelly said.

In a slight easing of language, Kelly said that the United States would not sit down with the North Koreans until they agreed to return to six-party disarmament talks which they abandoned earlier this year.

The United States has long insisted that any bilateral talks come only within the framework of six-party talks, which also include China, Japan, Russia and South Korea.

"We are fully aware that the North Koreans would like to have bilateral talks but they are also fully aware of our position on this -- that we will not have bilateral talks until they agree to return to six-party talks," Kelly said.

Pressed on whether he meant the United States could speak to the North before an actual resumption of multilateral discussions, Kelly said: "If they agree to six-party talks, then we'll sit down with them."

North Korea has made a series of conciliatory gestures in recent weeks, climbing down from months of tension earlier this year in which it tested a nuclear bomb and fired a missile over Japan.

South Korea's JoongAng Ilbo newspaper, quoting unnamed diplomatic sources, said earlier that Bosworth had accepted an invitation and would head to Pyongyang next month.