By Susan Cornwell
WASHINGTON (Reuters) - The top Republican in Congress on Wednesday sharpened his criticism of President Barack Obama's handling of military operations in Libya, pressing Obama over the mission's cost, leadership and exit strategy.
House of Representatives Speaker John Boehner, in a letter to the Democratic president, asked Obama how he would measure success in Libya and whether Libyan leader Muammar Gaddafi had to depart before the U.S. military involvement ends.
Obama is facing increasing unease in the U.S. Congress over the Libya operation, control of which the United States is seeking to relinquish in the coming days.
Boehner did not quibble with the idea of protecting civilians in Libya against attacks by Gaddafi's forces. But he expanded on concerns he initially raised on Sunday about a lack of clarity and consultation regarding the mission.
He also asked Obama if the Pentagon has made an estimate of the financial cost of the mission, how long American forces will remain involved after U.S. control is relinquished, and whether the United States will assume a greater or lesser role if the current coalition carrying out the mission falls apart.
"I respect your authority as Commander-in-Chief and support our troops as they carry out their mission," Boehner wrote.
"But I and many other members of the House of Representatives are troubled that U.S. military resources were committed to war without clearly defining for the American people, the Congress, and our troops what the mission in Libya is and what America's role is in achieving that mission."
Obama wrote to Congress on Monday saying that the strikes on Libyan government forces and air defenses are aimed at preventing a humanitarian disaster in Libya. The effort began on Saturday after the U.N. Security Council last Thursday approved a resolution calling for a no-fly zone over Libya.
A key question from Boehner was whether Obama thought it acceptable for Gaddafi to stay in power after the military operations against his forces end -- and if not, "how will he be removed from power?"
"What is your benchmark for success in Libya?" he asked.
CONSULTING WITH FOREIGNERS
Boehner noted that while Obama has said Gaddafi should go, the U.N. resolution does not insist on this. Such a resolution, the House speaker said, "does not substitute for a U.S. political and military strategy."
While the Obama administration has "consulted extensively" with foreign entities such as the Arab League and the United Nations, it has made a "limited, sometimes contradictory" case for the mission to the American people, Boehner said.
He said it was not clear how soon the United States expects to hand over control of operations in Libya to international partners, which ones would take the lead, or how long U.S. military forces would stay engaged.
Criticism of Obama has come from across the U.S. political spectrum for not consulting more with lawmakers before launching the Libya operation. The top Democrat in the House, Nancy Pelosi, issued a statement on Wednesday saying U.S. participation in the Libya effort "is strengthened by the president's continued consultation with Congress."
The House Foreign Affairs Committee has invited Secretary of State Hillary Clinton or another U.S. official to testify about Libya next week, a House aide said.
In the Senate, Republican Senator Richard Lugar asked Foreign Relations Committee Chairman John Kerry to hold hearings on the Libya intervention, saying lawmakers need to be able to ask the administration about the goals and strategy.
(Editing by Will Dunham)