As America's NATO allies shoulder a greater share of the air war in Libya, the Arab countries that urged the U.N. Security Council to impose a no-fly zone are missing from the action.

Except for the small Persian Gulf nation of Qatar, which is expected to start flying air patrols over Libya by this weekend, no other members of the 22-member Arab League have so far publicly committed to taking an active role. The U.S. has sold many of these countries, including Saudi Arabia and the United Arab Emirates, billions of dollars in sophisticated military gear over the past decade to help counter Iran's power in the region.

Nearly a week into the campaign to prevent Libyan leader Muammar Qaddafi's forces from attacking civilians, the United States increased the pressure on its NATO allies to take command of the campaign, suggesting the U.S. might even step away from its leadership role in a few days, even with the conflict's outcome in doubt.

Despite the threat, officials said there was no absolute deadline to hand over front-line control to other countries, or for an end to all U.S. participation. Still, with the costs of the campaign growing by the day and members of Congress raising complaints over the goals in Libya, the Obama administration wants its allies to take the lead role soon.

Defense Secretary Robert Gates, an early skeptic of American military intervention in Libya, said President Barack Obama made clear from the start of the campaign last Saturday that the U.S. would run it for only about a week. In an exchange with reporters traveling with him in Cairo on Wednesday, Gates was asked if his comments meant the U.S. had set a firm deadline of this Saturday for turning over command.

"I don't want to be pinned down that closely," Gates replied. "But what we've been saying is that we would expect this transition to the coalition, to a different command and control arrangement, to take place within a few days and I would still stand by that."

An American Army general now oversees the campaign from Europe, and an American Navy admiral is the day-to-day commander from a floating command post off the Libyan coast.

While the question of overall command remains unsettled, the Defense Department on Wednesday released statistics showing U.S. aircraft are flying fewer missions than at the beginning of the week.

Between Tuesday and Wednesday, there were 175 air missions — including non-combat flights — in the Libya operation, according to the department's figures. Of that total, 65 percent were flown by U.S. planes and 35 percent were flown by allied aircraft. Three days earlier, the U.S. made 87 percent of the flights compared with 13 percent by allied aircraft.

But when, or if, any Arab League members besides Qatar will participate is unclear.

On March 12, the Arab League called for the no-fly zone over Libya, saying Qaddafi's government had "lost its sovereignty. Yet since then, Arab League Secretary-General Amr Moussa has said the air war has caused civilian deaths and gone beyond what the league had backed.

On Tuesday, two Qatar Air Force fighter jets and a cargo jet flew to a Greek air base on the island of Crete, en route to helping enforce the no-fly zone. Navy Adm. Samuel J. Locklear, the day-to-day commander, said he expected Qatar's aircraft to "be up and flying in the coalition by the weekend."

Deputy national security adviser Ben Rhodes told reporters traveling with the president on Air Force One that the U.S. is continuing to talk to Arab states like Jordan and the United Arab Emirates. "Different countries are going to have different contributions to make here," he said.

In Congress, meanwhile, the Republican speaker of the House, Rep. John Boehner of Ohio, said Obama must quickly spell out the nation's precise goals in Libya. Congressional liberals and conservatives have criticized the president — some accusing him of acting too slowly, others saying he moved too quickly. Some have said he should have asked for Congress' approval before committing U.S. troops to combat.

Secretary of State Hillary Rodham Clinton said order could be resolved quickly — if Libyan leader Moammar Qaddafi would just quit.

Obama returned Wednesday to Washington after a three-nation tour of Latin America, and several key Democrats lined up in support of his approach in Libya.

Sen. Dick Durbin of Illinois, the No. 2 Senate Democrat, said that when Qaddafi started a violent crackdown on his people, Obama moved with "unprecedented speed," and when Qaddafi remained defiant, Obama worked with allies and the Arab nations. He called it a "prudent course of action for the president and for our nation."

But, Boehner, in a letter to the White House, said Obama still must provide a clear and robust assessment of the mission and how it will be achieved. Boehner did not call for a vote in the House on the commitment of U.S. military resources, as some lawmakers have demanded.

Administration officials conceded there is no clear end to the fighting, although the Pentagon contended that Qaddafi's air force is essentially defeated and coalition planes are targeting more of his ground forces.

In a telephone interview with reporters at the Pentagon from aboard his command ship, the USS Mount Whitney, in the Mediterranean, Navy Rear Adm. Gerard Hueber said no Libyan aircraft had attempted to fly during the previous 24 hours.

"Those aircraft have either been destroyed or rendered inoperable," Hueber said.


Associated Press writers Lolita C. Baldor, Robert Burns, Donna Cassata, Anne Gearan, Pauline Jelinek and Matthew Lee contributed to this report.