Washington ? John Bolton, the U.S. ambassador to the United Nations, Wednesday opposed a bill to withhold more than $130 million in funding to the world body unless it implements congressionally mandated reforms.

In his first appearance before Congress since becoming U.N. ambassador, Bolton warned Rep. Henry Hyde, R-Ill., the powerful chairman of the House International Relations Committee who sponsored the bill, and other members of that panel that the legislation would undercut the president’s authority to make foreign policy.

“I’ve been an executive branch official my entire public career and, for both constitutional and historical reasons, the executive branch appropriately has typically opposed automatic, nondiscretionary directions from all of you esteemed ladies and gentlemen,” Bolton said.

Bolton’s remarks, coming from the administration’s sharpest U.N. critic, were expected to deal a serious blow to those efforts.

Hyde nevertheless continued to make his case, saying “withholding dues is a wonderful way to get their attention” at the United Nations.