Analysts and officials said Kim's pledge may be a sign the North is backing down from its high-stakes brinkmanship in the face of unified international pressure, including a push by its main benefactor, China, to restart the stalled talks.
China sent Wang Jiarui, head of the Communist Party's liaison department, to Pyongyang on Saturday to try to revive the talks.
"We will go to the negotiating table anytime if there are mature conditions for the six-party talks thanks to the concerted efforts of the parties concerned in the future," KCNA quoted Kim as telling the Chinese envoy.
Kim said he hoped the United States would show "trustworthy sincerity and move," KCNA said.
That remark was an apparent reference to North Korean demands that Washington drop what Pyongyang calls its hostile attitude and provide guarantees for North Korea's security. China has played host to three rounds of the six-way talks aimed at ending Pyongyang's nuclear programmes in return for aid and security guarantees.
North Korea had never opposed the six-party talks and was committed to de-nuclearisation of the Korean peninsula, Kim said. His country has been branded by US President George W. Bush as part of an "axis of evil" along with Iran and pre-war Iraq.
The new US lead negotiator to the talks, Ambassador to South Korea Christopher Hill, said China would propose the next step in the process but declined to say whether Beijing would soon call a meeting of the six parties.
"We'll wait to see what the host of the six-party talks has to say and whether they're going to schedule something in the near future," he told reporters. "The DPRK's future depends on coming to these talks and beginning a long road, a difficult road for them but an essential road for them to return to the international community," Hill said earlier at a breakfast meeting.
China urged the United States to address North Korea's concerns. "We hope that all sides, especially the party of direct concern, will earnestly consider these questions," Foreign Ministry spokesman Kong Quan told a news conference after Wang's return, referring to Pyongyang's demands.