By Ross Colvin and Patricia Zengerle
WASHINGTON (Reuters) - The White House pushed back on Monday against pressure from some lawmakers for direct intervention in Libya, saying it first wanted to figure out what various military options could achieve.
"It would be premature to send a bunch of weapons to a post office box in eastern Libya," White House spokesman Jay Carney said. "We need to not get ahead of ourselves in terms of the options we're pursuing."
The Obama administration faces sharp criticism, especially from Republican lawmakers and conservative commentators, for its cautious approach to the turmoil in Libya but has signaled it will not be rushed into hasty decisions that could suck the military into a new war and fuel anti-American sentiment.
One major obstacle: officials are still trying to identify the main actors within the opposition groups fighting to oust Libyan leader Muammar Gaddafi. The aims of these groups are unclear, including what type of government they might set up if Gaddafi falls, the officials say.
President Barack Obama said on Monday he wanted to "send a very clear message to the Libyan people that we will stand with them in the face of unwarranted violence and the continuing suppression of democratic ideals that we've seen there."
The White House has long said all options are on the table over Libya but, on Monday for the first time, it gave a vague priority to the possible military steps being studied.
Bottom of the list is sending in ground troops, Carney told a briefing. A "no-fly" zone, an idea popular with lawmakers, is being "actively" discussed within NATO, while possibly arming the rebels is also in the mix, he said.
Brian Katulis, a Middle East expert who has informally advised the White House on the turmoil sweeping the region, said the Obama administration is constrained by its reluctance to act militarily without international support.
The calls from lawmakers for more action would create a "little bit of pressure" on the White House, he said, but not enough to force a course of action it sees as perilous.
Defense Secretary Robert Gates reiterated on Monday that any intervention in Libya would require broad backing.
"At this point there is a sense that any action should be the result of international sanction," he said during a trip to Afghanistan.
Underscoring the lack of consensus, Russian Foreign Minister Sergei Lavrov said Moscow opposed military intervention. China, a fellow veto-wielding member of the U.N. Security Council, has expressed similar misgivings.
NATO Secretary-General Anders Fogh Rasmussen said on Monday the alliance would intervene only if the U.N. Security Council called for it.
The United States has deployed two amphibious assault ships off the Libyan coast, ostensibly to help with any humanitarian emergencies, while dispatching military transport aircraft to airlift stranded Egyptian refugees from neighboring Tunisia.
Over the weekend, leading Republican and Democratic senators urged Obama to do more to help Libya's rebels, who have fought Gaddafi's security forces to a standstill in some areas but are facing repeated air strikes.
Mitch McConnell, the top Republican in the Senate, said one option was "simply aiding and arming the insurgents," noting that the United States often did this during the Cold War.
John Kerry, the influential chairman of the Senate Foreign Relations Committee who is close to Obama, repeated his call for a no-fly zone and floated another idea -- bombing Libyan runways to ground Gaddafi's warplanes.
Pentagon spokesman Colonel Dave Lapan cautioned that a limited strike on runways would not stop helicopter gunships from taking off. Helicopters were reported to have been involved in air strikes against rebels at the weekend.
Senator John McCain said he favored providing intelligence and technical assistance to the rebels and declaring U.S. support for a provisional Libyan government.
(Additional reporting by Caren Bohan, Matt Spetalnick and Susan Cornwell; Editing by John O'Callaghan and Cynthia Osterman)