A day after his White House meeting with President Barack Obama, U.N. Secretary-General Ban Ki-moon called the United States a "deadbeat" donor to the world body while making the made the rounds on Capitol Hill.

Ban's criticism Wednesday of the U.N.'s single biggest backer irked some members of the House Foreign Relations Committee. They were generally supportive of his leadership but voiced concern about U.N. efforts in areas from Sudan to Somalia.

"He used the word 'deadbeat' when it came to characterizing the United States. I take great umbrage (over) that," Ileana Ros-Lehtinen, the panel's senior Republican, said after an hour-long, closed-door meeting. "We certainly contribute a whole lot of U.S. taxpayer dollars to that organization. We do not deserve such a phrase.

Interviewed after the session, Ban said he had wanted to draw attention to the fact that the U.S. agrees to pay 22 percent of the U.N.'s $4.86 billion operating budget, but is perennially late with its dues -- and now is about $1 billion behind on its payments.

That figure is "soon to be $1.6 billion," Ban emphasized. Asked if he'd used the word 'deadbeat' during the meeting, he replied, "Yes, I did -- I did," then laughed mischievously.

Ban also urged Congress to adopt climate change legislation to boost chances for his top goal this year: clinching a global climate deal. The hope is for accord at a U.N.-sponsored conference in Copenhagen in December.

"I believe for the United States it's a necessity. It will have a very politically important impact on the ongoing negotiation," he said. "We need the U.S. leadership at this time. Whole world is looking at U.S. leadership."

Ban generally got a "very respectful" reception from the House committee, said Rep. Bill Delahunt, D-Mass., who chairs a subcommittee that oversees U.S. participation in the United Nations.

"Clearly they have an interest in the United States meeting its responsibility. In terms of peacekeeping, we're about $670 million behind, and I think the argument is well-stated," Delahunt said.

He noted America backs U.N. peacekeeping operations -- and said it loses credibility if it doesn't provide financial support. "And at the same time, we have to recognize that there are no American troops involved in the 17 different venues where there are peacekeeping operations," Delahunt said.

Ban was also meeting with Sen. John Kerry, D-Calif., the Senate Foreign Relations chairman, and other committee members.

During an Oval Office session Tuesday, Obama pledged to work to help bring peace to Darfur and called it "not acceptable" that Sudan's president has been kicking out humanitarian aid workers from the region of western Sudan. President Omar al-Bashir was charged in an International Criminal Court arrest warrant with war crimes and crimes against humanity for targeting civilians.

Ban told Obama his support for climate legislation is "encouraging", but said 2009 is a "make-or-break" year for the U.N. and its member countries on global warming, Darfur and other prominent conflicts.

"It's the beginning of the establishment of a close relationship between the two," said Peter Yeo, a vice president for the U.N. Foundation, launched by media mogul Ted Turner's $1 billion donation in 1997.

Yeo, a former House Democratic staffer and foreign policy adviser to both the Obama and Hillary Rodham Clinton campaigns last year, said Obama's budget proposal also is a hopeful sign for the U.S.-U.N. relationship.

Obama seeks a 9.5 percent increase in international affairs spending, which Yeo said would be enough to cover not only next year's U.S. dues to the U.N., but also $1 billion in arrears.