The White House said Sunday North Korea should first prove its seriousness about dialogue through actions, "not nice words," effectively turning down the communist nation's offer of bilateral negotiations without "preconditions" attached.

"Those talks have to be real. They have to be based on them living up to their obligations, to include on proliferation, on nuclear weapons, on smuggling and other things," said Denis McDonough, President Barack Obama's chief of staff.

"So we'll judge them by their actions, not by the nice words that we heard yesterday," he told the "Face the Nation," a CBS talk show.

He was referring to a statement by North Korea's National Defense Commission proposing high-level talks with the U.S.

Pyongyang's sudden offer was in line with its recent charm offensive following months of provocations and military threats.

Earlier this month, the North sought high-level dialogue with the South but the two sides failed to arrange it amid disputes over the rank of top delegates.

McDonough indicated that Washington views Pyongyang's overtures as aimed at evading economic sanctions.

"I will say that the bottom line is they're not going to be able to talk their way out of the very significant sanctions they're under now, sanctions that Russia supported and -- very importantly -- that China supported," he stressed.

White House National Security Council spokeswoman Caitlin Hayden also said the U.S. wants to have "credible negotiations"

with North Korea for the ultimate goal of denuclearizing the communist nation.

"We have always favored dialogue and, in fact, have open lines of communication with the DPRK (North Korea)," she said in a statement emailed to Yonhap News Agency.

"But those talks must involve North Korea living up to its obligations to the world, including compliance with UN Security Council Resolutions, and ultimately result in denuclearization," Hayden added.

The White House's formal response came about nine hours after the North's announcement that it wants high-profile negotiations with the U.S. to ease tensions on the peninsula.

It was not confirmed whether the U.S. and North Korea had direct contact over the latest dialogue offer.

A senior U.S. government official, meanwhile, said the U.S. will discuss the matter with South Korea and Japan when their top diplomats handling the North Korea issue meet in Washington later this week.

"We will be meeting with our Japanese and South Korean partners in a trilateral setting and this will be one of the subjects for discussion," the official said on the condition of anonymity.

Cho Tae-yong, South Korea's special representative for Korean Peninsula peace and security affairs, is scheduled to visit Washington from Tuesday through Thursday.

On Wednesday, he plans to hold a trilateral meeting with his American and Japanese counterparts -- Glyn Davies and Shinsuke Sugiyama.

Speaking at a Washington seminar last week, Davies said the U.S. has no plans to talk with North Korea at this moment.

"The United States will not engage in talks merely for the sake of talks," he said at the forum co-hosted by the Kyungnam University's Institute for Far Eastern Studies (IFES) and the Woodrow Wilson International Center for Scholars (WWICS).

"What we want are negotiations that address the real issue at hand; North Korea's nuclear program," he added. "Authentic and credible talks will require a serious, meaningful change in North Korea's priorities demonstrating that Pyongyang is prepared to meet its commitments and obligations to achieve the core goal of the September 2005 joint statement, the verifiable denuclearization of the Korean Peninsula in a peaceful manner."

The U.S. will never accept North Korea as a nuclear-armed state, he added. (Yonhap News)