Rodrigo Abd, Associated Press
In this photo taken Monday, May 23, 2011, men walk next to a destroyed tank in Tripoli Street, the center of fighting between forces loyal to Libyan leader Moammar Gadhafi and rebels in downtown Misrata, Libya. Since the weeks-long siege of the city ended in mid-May, Misrata residents make pilgrimages to Tripoli Street, site of the fiercest fighting in the battle for Libya between the rebels and Moammar Gadhafi's forces. People gawk at the wreckage of bombed-out buildings with gaping holes and walls pocked by bullets, and shoot photos of charred hulks of tanks, rubble-strewn streets and a side walk museum featuring drumloads of bullet casings, uniforms of dead enemies, and unexploded munitions.

WASHINGTON — The House of Representatives postponed on Wednesday a vote on a resolution that would demand an end to U.S. involvement in Libya amid fears that Democrats and Republicans would unite in backing the measure and hand President Barack Obama an embarrassing foreign policy defeat.

Republican leaders had scheduled a vote on the resolution by Democratic Rep. Dennis Kucinich that "directs the president to remove United States armed forces from Libya ... not later than 15 days after the adoption" of the measure. The vote was abruptly delayed as the leaders and Obama administration realized frustrated lawmakers probably would support it.

Nearly three months after Obama launched air strikes to back the rebels battling Libyan leader Moammar Gadhafi, lawmakers are exasperated with the administration's inability to spell out a strategy, said one Republican leadership aide, speaking on condition of anonymity to freely describe the situation.

Forces loyal to Gadhafi and the rebels remain in a standoff as NATO and its partners said Wednesday they have decided to extend for another 90 days their military campaign to protect Libyan civilians.

House Republican leaders plan to hold a special meeting Thursday to weigh Congress' next steps, including the possibility of rescheduling a vote on the resolution.

In an interview with reporters Wednesday, Republican Speaker John Boehner, the senior lawmaker in the House, said no decision will be made until after Thursday's meeting. Asked if the White House had contacted him about putting off the vote, Boehner said, "No ... that would require someone picking up the phone."

Boehner said he is still seeking answers to questions he raised in a March 23 letter to Obama, the commander in chief, including a clear description of the U.S. mission, the cost of the operation and U.S. objectives.

"The American people deserve answers to these questions. And all of these concerns point to a fundamental question: What is your benchmark for success in Libya?" Boehner wrote.

In a statement Wednesday, Kucinich said Republican leaders told him the vote had been delayed to obtain more information and consult with the administration.

"I am disappointed that the president and leadership feel the need to buy even more time to shore up support for the war in Libya," Kucinich said. "It's not surprising that some are now wondering if a preliminary vote count on my resolution came out in favor of defending the Constitution."

Kucinich said Obama violated the Constitution because only Congress has the power to declare war. The lawmaker also said Obama violated the War Powers Act, which requires congressional authorization 60 days after the start of military operations.

Asked if Obama was in violation of the War Powers Act, Boehner said, "technically, no."

Obama spokesman Jay Carney defended the U.S. action in Libya and said Obama is not exceeding his powers in keeping the U.S. involved in the NATO-led campaign.

"We feel strongly that the president has acted in a way that is consistent with the war powers resolution," he said.

Administration officials held a classified briefing for lawmakers Wednesday, and stressed that any congressional action backing away from Libya would undermine U.S. standing within NATO, said Democratic Rep. Gary Ackerman, a member of the House Foreign Affairs Committee.

Ackerman suggested politics played a role in some Republican opposition to Obama's actions against Libya.

"It's really a policy of being against him (Obama)," Ackerman said. He said Republicans "are making a choice between Moammar Gadhafi and Barack Obama."

Obama backs a Senate resolution written by Sens. John Kerry, Democratic chairman of the Senate Foreign Relations Committee, and John McCain, the committee's senior Republican, supporting the U.S. military role in the NATO-led operation. The Senate could vote on that resolution next week.

Last week, the House overwhelmingly backed an amendment to a defense bill that would bar any U.S. money for U.S. ground forces or private security contractors in Libya except for those involved in rescue missions of U.S. service members. The vote was 416-5.

Obama recently said the U.S. involvement is limited in the NATO-led operation. He also has said he would not send ground forces.

AP Special Correspondent David Espo contributed to this report.