NATO to U.S.: We Need More Strikes in Libya U.S. agrees to continue strikes; lack of U.S. flights blamed for rebel losses.

WASHINGTON, April 3, 2011 -- NATO has asked the United States to continue participating in airstrikes over Libya through late Monday, ABC News has learned.

This was done to make up for the bad weather earlier in the week that had hampered targeting of Gadhafi forces and allowed them to push the rebels back to Ajdabiyah.

The United States was supposed to have significantly begun dropping its participation in airstrikes over Libya.

"Due to poor weather conditions over the last few days in Libya, the United States has approved a request by NATO to extend the use of some U.S. strike aircraft," NATO spokeswoman Oana Lungescu told ABC News. "These aircraft will continue to conduct and support Alliance air-to-ground missions throughout this weekend."

A U.S. Defense Department official said the aircraft Lungescu was referring to are the A-10 Thunderbolt jets, Marine AV-8 Harrier jets and AC-130 gunships, which are the best suited for striking ground force targets.

During testimony on Capitol Hill Thursday, Defense Secretary Robert Gates and Joint Chiefs of Staff Chairman Adm. Mike Mullen said that beginning Saturday these aircraft would be on stand-by mode if NATO commanders requested them. That appears to have happened.

Several senators at Thursday's hearing were upset to hear the news, saying U.S. timing to scale back participation was unfortunate given the ongoing rout of the rebels.

Sen. John McCain, R-Ariz., sarcastically called the timing "exquisite."

Another Defense official said the NATO request was specifically tied to making up for the bad weather that "prohibited strikes from being as effective as they might have been and allowed Gadhafi's forces to take advantage and regain territory."

This official said there was no drop off in U.S. strike participation as had been anticipated.

New numbers show there was not a dropoff in U.S. flights Saturday.

Through 6 a.m. ET, there were 81 U.S. flights, including 40 strike flights and 40 support missions.

Three Harrier jets were involved in missions Saturday, a Defense official said.

A number of U.S. combat forces had been scheduled cease operations today, including U.S. Navy destroyers and submarines that have been launching Tomahawk cruise missiles from the Mediterranean.

Military experts said that America's reduced role in enforcing the Libyan no-fly zone could cripple efforts to keep Gadhafi's forces from battering the rag-tag army trying to topple him.

They said they fear that without U.S. willingness to go after Gadhafi's troops and equipment from the air, and without U.S. ground controllers pinpointing targets, the effort to shield the rebels will fail.

"The idea that the AC-130s and the A-10s and American air power is grounded unless the place goes to hell is just so unnerving that I can't express it adequately," said Sen. Lindsay Graham, R-S.C. "The only thing I would ask is, please reconsider that."