David Wood contributed to this report.
WASHINGTON -- On Sunday, Sen. Richard Lugar (R-Ind.) raised questions about the economic costs of U.S. involvement in Libya.
Speaking on NBC's "Meet The Press," Lugar insisted that the U.S. has no vital national security interest in Libya and argued that additional military spending will exacerbate the nation's budget deficit.
"There have to be objectives and a plan and an agreement that we're prepared to devote the military forces but also the money," Lugar said. "It makes no sense in the front room, where in Congress we are debating seemingly every day the deficits, the debt ceiling situation coming up, the huge economic problems we have -- but in the back room we are spending money on a military situation in Libya."
President Obama committed U.S. forces in Libya amid escalating violence, in which Libyan leader Muammar Gaddafi pledged to show "no mercy" to those opposing his regime.
Other members of Congress have been critical of Obama's Libya decision, presenting arguments that many congressional Democrats had used to critique President George W. Bush's handling of the Iraq war. But in recent years, Lugar has developed a record of questioning U.S. military efforts that other top Republicans have supported.
After initially supporting the Iraq invasion, Lugar broke with President Bush and his party in 2007 by calling for a reduced American role in Iraq. He has also criticized continued U.S. involvement in Afghanistan over the past year, noting the costs of the operation and unclear military objectives.
Rep. Justin Amash (R-Mich.) introduced legislation last week to immediately halt military action in Libya unless the president receives authorization from Congress. Rep. Bruce Braley (D-Iowa) has also pressed the administration for a full accounting of the costs of U.S. involvement, saying he has not yet received a straightforward answer from the White House.
Administration officials are not planning on asking Congress for a supplemental bill to pay for the military intervention in Libya, which National Journal estimated cost more than $100 million in Tomahawk missiles alone in its first day. "The operation in Libya is being funded with existing resources at this point. We are not planning to request a supplemental at this time," Office of Management and Budget spokesman Kenneth Baer said Monday.
In an interview with Jake Tapper on ABC's "This Week," Defense Secretary Robert Gates refused to estimate the length of the U.S. commitment in Libya. When asked by Tapper whether American troops would be withdrawn by the end of the year, Gates responded, "I don't think anybody knows the answer to that."
Gates was also cautious about defining American objectives in Libya, noting that "regime change is a complicated business," and suggesting that a full ouster of Gaddafi may not be a final goal of the U.S. mission.
In a separate interview for "Meet the Press," Gates acknowledged that Libya does not represent a clear threat to U.S. national security interests, but said that other considerations make the military mission important.
"I don't think it's vital interest of the United States, but we clearly have interests there," Gates said. "And it's a part of the region which is a vital interest for the United States."
Sens. Jim Webb (D-Va.) and Edward Markey (D-Mass.) have both suggested the U.S. implemented its no-fly zone out of concerns over the stability of oil prices. Rising oil prices are crimping American consumers amid a fragile economic recovery.
But Lugar questioned whether the money being spent on military operations in Libya would be better spent elsewhere.
"Estimates are that about $1 billion has already been spent on an undeclared war in Libya, some would say only hundreds of millions, and that that will diminish in the days ahead," Lugar said. "But [who] knows how long this goes on? And furthermore, who has really budgeted for Libya at all? I have not really heard the administration come forward saying that, 'We're going to have to devote these funds, folks, and therefore it's something else we'll have to go or it simply adds to the deficit.'"
Secretary of State Hillary Clinton also made the Sunday talk show rounds with Gates. In an interview on ABC, Clinton insisted that international cooperation made the U.S. mission in Libya a more manageable operation than the war in Iraq, and one that does not need the same level of congressional approval. Sen. Carl Levin (D-Mich.) made similar statements on CNN's "State of the Union."
"There was no U.N. support in Iraq. It made a big difference," Levin said. "We're part of an international coalition which has been supported now by U.N. resolution, the support of Arab countries, to prevent the slaughter of civilians in Libya."
When Tapper asked why President Obama chose to intervene in Libya, after declining to commit U.S. troops to unrest in other Middle East nations, Clinton said the severity of the violence in Libya had touched a particular humanitarian nerve in the international community.
"Each of these situations is different," Clinton responded. "But in Libya, where a leader says 'spare nothing, show no mercy' and calls out air force attacks on his own people, that crosses a line."
The conflict in Libya, an oil-rich, Alaska-sized desert nation in North Africa, began quietly enough in its eastern city of Benghazi, where anti-government protests erupted Feb. 15. Within days demonstrators had ransacked the state TV offices in Tripoli, and Libyan diplomats began defecting. By Feb. 22, Gaddafi had ordered his military to crush the growing demonstrations. Tens of thousands fled across Libya's borders into Tunisia and Egypt. On Feb. 25 President Obama imposed sanctions on Libya, freezing $32 billion in Gaddafi's assets.
Demonstrators and rebel forces, which may include anti-American radicals, seized much of eastern Libya as fighting intensified. By March 3, Gaddafi's warplanes were bombing civilians in the oil port of Brega. President Obama declared that Gaddafi "must leave" and ordered the Pentagon to begin exploring all options against the Libyan regime. By March 17, with Libyan civilians and rebels increasingly bloodied by Gaddafi’s forces, the U.N. Security Council, under U.S. and European pressure, authorized a no-fly zone and protection of civilians.
American ships and submarines unleashed a barrage of 124 Tomahawk cruise missile attacks on Saturday, March 19, and U.S. and allied warplanes, including three bat-winged B-2 bombers, flying from Whitman air force base in Missouri, struck Libyan airfields and aircraft shelters, command centers and armored columns in the opening hours of Operation Odyssey Dawn. By March 24, NATO had agreed to take over command of the no-fly zone and missions to protect civilians. Protecting civilians from the air, however, remained extremely difficult, and as the conflict headed into a bloody stalemate, confusion continued about the precise goals of the U.S. and allied military action -- in particular whether the military mission of "protecting civilians" ultimately means removing Gaddafi by force.