By Patricia Zengerle and Susan Cornwell
WASHINGTON (Reuters) - Secretary of State John Kerry briefly opened the door on Tuesday to authorizing U.S. ground troops in Syria, but quickly slammed it shut and told Congress that any resolution approving military force would prohibit "boots on the ground."
The exchange during the first public hearing in Congress on possible military action in Syria highlighted the worries of many lawmakers about authorizing U.S. military strikes to punish the Syrian government for using chemical weapons on civilians.
Kerry initially told the Senate Foreign Relations Committee he would prefer not to bar the use of ground troops in Syria to preserve President Barack Obama's options if Syria "imploded" or there was a threat of chemical weapons being obtained by extremists.
"I don't want to take off the table an option that might or might not be available to a president of the United States to secure our country," Kerry told the committee.
But when Senator Bob Corker of Tennessee, the top Republican on the committee, told Kerry he "didn't find that a very appropriate response regarding boots on the ground," Kerry quickly, and repeatedly, backtracked.
Kerry said he was simply "thinking out loud" and raising a hypothetical situation, but he did not want to leave the door open to sending ground troops to Syria.
"Let's shut the door now," Kerry said. "The answer is, whatever prohibition clarifies it to Congress or the American people, there will not be American boots on the ground with respect to the civil war."
The exchange came as Kerry, Secretary of Defense Chuck Hagel and General Martin Dempsey, chairman of the Joint Chiefs of Staff, visited Capitol Hill as part of the administration's push to persuade Congress to back Obama's plan to launch limited strikes on Syria for its alleged use of chemical weapons last month.
Obama has asked Congress, which does not return in full from summer recess until next week, to authorize action in response to what the administration says was a sarin gas attack by the Syrian government that killed more than 1,400 people, hundreds of them children, near Damascus on August 21.
Significant opposition to military force remains in Congress, where many lawmakers, including Obama's fellow Democrats, have said they are concerned the president's draft resolution is too open-ended and allow possible use of ground troops or eventual attacks on other countries.
A Reuters/Ipsos poll released on Tuesday showed Obama has failed to convince most Americans of the need for a military strike in Syria. Some 56 percent of those surveyed said the United States should not intervene in Syria, while only 19 percent favored action, the online poll found.
The hearing was interrupted several times by shouting protesters from the anti-war group Code Pink who were escorted away by Capitol police.
NO SUPPORT FOR 'BOOTS ON THE GROUND'
"I don't think there are any of us here that are willing to support the possibility of having combat boots on the ground," Corker said.
The resolution proposed by the administration authorizes Obama to use military force as necessary to "prevent or deter the use or proliferation" to or from Syria of any weapons of mass destruction, including chemical weapons
One of the leading hawks on Syria in Obama's cabinet, Kerry assured lawmakers it would be easy to word a resolution on military force to reassure Congress and the public that the door in Syria was not open to ground troops.
But Kerry also urged senators not to limit U.S. authority to strike Syria to "one specific moment," saying the military had follow-on strike options should Syria's government use chemical weapons again.
Senators Robert Menendez and Corker, the Democratic and Republican leaders of the committee, announced late on Tuesday that they had reached an agreement on a draft resolution authorizing force, paving the way for a committee vote on Wednesday.
Among other things, the resolution sets a 60-day time limit for any engagement and bars the use of U.S. armed forces on the ground in Syria for combat operations.
Two members of the House of Representatives, Democrats Gerald Connolly and Chris van Hollen, offered their own version of the legislation, which would also prohibit U.S. "boots on the ground" and limit any engagement to 60 days.
The House must pass its own version of the authorization for the use of military force and the Senate and House versions must be reconciled before Obama can sign it.
During their appearance, Kerry and Hagel told the committee that any military operation would be limited and specifically designed to degrade President Bashar al-Assad's chemical weapons capability.
Hagel added that a failure to punish Syria for the use of chemical weapons would damage U.S. national security interests and American credibility.
"A refusal to act would undermine the credibility of America's other security commitments - including the president's commitment to prevent Iran from acquiring a nuclear weapon," he said. "The word of the United States must mean something."
As Kerry and Hagel pressed their case for limited military strikes in Syria, Obama won support for action from two top Republicans in the House of Representatives - Speaker John Boehner and Majority Leader Eric Cantor.
"Only the United States has the capability and the capacity to stop Assad and to warn others around the world that this type of behavior is not going to be tolerated," Boehner told reporters. "I believe that my colleagues should support this call for action."
Kerry, Hagel and Dempsey are due to appear before the House Foreign Affairs Committee on Wednesday.
(Reporting by Mark Felsenthal, Susan Heavey, Vicki Allen, Arshad Mohammed, Phil Stewart, Tom Ferraro, David Lawder, Richard Cowan and Jeff Mason; Writing by John Whitesides; Editing by Karey Van Hall, Alistair Bell and Philip Barbara)