Apparently rebuffing North Korea's call for "unconditional" nuclear talks, the U.S. government urged the communist nation Wednesday to first demonstrate its seriousness on dialogue through action, not just rhetoric.

"The onus is on North Korea to take meaningful actions toward denuclearization and refrain from provocations," a State Department official said, adding it reflects Washington's formal stance.

The official pointed out Pyongyang committed to abandoning all nuclear weapons, including in the September 2005 Joint Statement with its dialogue partners in the now-suspended six-party talks.

The other parties are South Korea, China, Japan and Russia.

"We will continue to hold the DPRK (North Korea) to those commitments and its international obligations," added the official.

The comments came in response to a public suggestion by North Korea's senior nuclear envoys at a forum held in Beijing Wednesday (local time).

"We are ready to enter the six-party talks without preconditions," First Vice Foreign Minister Kim Kye-gwan said during the one-day event organized by China's foreign ministry as part of its efforts to revive the six-party talks.

South Korea, the U.S. and Japan sent lower-ranking diplomats and academics to the session. Another U.S. government official earlier said U.S. government participation at the event was handled by its embassy in Beijing.

Kim accused Washington and Seoul of setting preconditions for the resumption of the six-way talks, last held in December 2008.

"Attaching preconditions to our offer of dialogue would cause mistrust," he added, calling on South Korea, the U.S. and Japan to re-start the six-party process "before it is too late."

(Yonhap News)