WASHINGTON (Reuters) - U.S. Secretary of State Hillary Clinton said on Thursday the United States had no plans to give North Korea economic aid and Pyongyang was digging a "deeper and deeper" hole by its latest actions.

"We have absolutely no interest and no willingness on the part of this administration to give them any economic aid at all," Clinton told lawmakers.

She was defending a budget request for nearly $100 million for future U.S. economic aid to North Korea.

"That money is in there in the event, which at this point seems implausible if not impossible, the North Koreans return to the six-party talks and begin to disable their nuclear capacity again," she said.

"They are digging themselves into a deeper and deeper hole with the international community," Clinton added at a hearing by the Senate Appropriations Committee.

Last December, the United States suspended fuel aid to the energy-starved North until it agreed to specific steps to verify its nuclear activities, which Pyongyang refused to do.

Kansas Republican Senator Sam Brownback said the request for future U.S. aid funds sent "exactly the wrong message" to the North.

"If North Korea doesn't perform then we should ... move quickly to reimpose sanctions that have been waived," Brownback said. "My goodness, if they haven't done enough to merit this situation."

North Korea on Wednesday threatened a new nuclear test unless the U.N. Security Council apologized for sanctions that were tightened after Pyongyang's April 5 rocket launch which the United States and other nations said was a disguised long-range missile test.

The impoverished North also said it would boycott the six-party disarmament talks that bring in the two Koreas, China, Russia, Japan and the United States. At the weekend, it said it had started extracting plutonium from spent fuel rods at its nuclear arms plant.

"We are very serious about trying to make it clear to the North Koreans that their recent behavior is absolutely unacceptable," Clinton said.

(Writing by Sue Pleming, additional reporting by Jeremy Pelofsky, editing by Alan Elsner)