U.S. Secretary of State John Kerry on Thursday dismissed North Korea's preconditions for talks as unacceptable.

Testifying at a Senate hearing, he stressed Washington will not let Pyongyang play a gambit to get assistance without taking sincere steps toward denuclarization.

But he said North Korea's talk of dialogue itself is positive.

After weeks of bellicose military threats, Pyongyang has been talking about the terms to restart dialogue.

In a statement, the North's military said if the U.S. wants dialogue it should roll back U.N. sanctions and end joint military exercises with South Korea.

"That's the first word of negotiation or thought of that we've heard from them since all of this has begun," Kerry said at the Senate Armed Services Committee. "So, I'm prepared to look at that as, you know, at least a beginning gambit -- not acceptable, obviously, and we have to go further."

The secretary emphasized the importance of breaking the pattern of negotiations with North Korea -- rewarding Pyongyang for returning to the bargaining table after provocative acts.

President Barack Obama's policy is "to try to change this dynamic, which has been just a round robin of disaster for the last 20 years," he said.

Kerry pointed out that Pyongyang has reneged on international deals, including the 1994 Agreed Framework.

"You reach agreement, they go back on it. You reach agreement again, you give them some food aid, there's some sort of bait, nothing happens," he said.

A problem is that North Korea has continued to progress in its nuclear weapons program, said Kerry.

Kerry, who traveled to Northeast Asia last week, expressed optimism that China will take the side of the U.S. and its allies in endeavoring to resume talks with North Korea.

"China sees a growing level of instability in the region," he said. "And the last thing they would want, I'm convinced, is a war on their doorstep or a completely destabilized Korean Peninsula."

Kerry added, "It is clear to me they are wrestling with their best approach. They're really thinking about this for a number of reasons."

In a sign that the U.S. and China are in close consultations on the North Korea issue, Wu Dawei, China's special representative for North Korea policy, plans to visit Washington next week, according to a U.S. government official.

Wu will visit Washington from Sunday till Wednesday for consultations with his American counterpart, Glyn Davies.

"Both the United States and China agree on the fundamental importance of a denuclearized North Korea,”the State Department official told Yonhap News Agency.

Wu is chairman of the six-way talks on North Korea's nuclear program, which also involve South Korea, Japan and Russia. The negotiations have been deadlocked for years amid Pyongyang's repeated provocative acts.

Earlier in the day, the White House insisted that the Sept. 19, 2005, deal at the six-party talks should be the basis for discussions if any negotiations with North Korea resume.

"The United States has been and remains open to authentic and credible negotiations that would implement the September 2005 statement of the six-party talks," White House spokesman Josh Earnest told reporters.

In the agreement, the North pledged to abandon all of its nuclear program in exchange for political and economic incentives.

The U.S. is open to "credible, authentic negotiations, but it's going to require clear signals from the North Korean regime... to live up to their international obligations and to keep their commitments to end their nuclear weapons program," he said. (Yonhap News)