By the recent standards of the fiercely partisan US lower house of Congress, controlled by the opposition Republicans, Wednesday's 273-156 vote was a bipartisan walk in the park. Leading politicians from both the Democrats and Republicans voiced support for arming and training moderate Syrian rebels, despite backbench resistance in the House of Representatives.

"This is the best of a long list of bad options," Democratic Congressman Jim Moran said after the vote, rejected by 71 Republicans and 85 Democrats.

"There are too many unanswered questions for me to support this amendment," California Democrat Barbara Lee said. "How will we ensure that the United States weapons we are providing to Syrian rebels will not get into the wrong hands, as they did with the rebels we supported in Libya?"

The motion still needs to clear the upper house, the Senate, with a vote possible as early as Thursday, before President Barack Obama could sign it into law. With mid-term elections due in November, the motion was only a temporary one, designed to authorize short-term action and spending until a new balance of power emerges in Congress.

Assistance here, airstrikes there

This mission to aid some opponents of Syrian President Bashar al-Assad could well coincide with strikes on Syrian territory against suspected members of the self-proclaimed "Islamic State" group, which has taken control of parts of the country during the protracted civil war. John Kerry made the US case for intervention in Iraq and Syria earlier on Wednesday, with his speech and that of Defense Secretary Chuck Hagel meeting jeers from the anti-war protest group CodePink.

The US had long criticized the Assad government's response to Syria's public uprising turned civil war, but offered comparatively little direct military aid to armed groups opposing the Syrian military. Oubai Shahbandar of the Syrian National Coalition - a western-backed opposition body - called the House vote "an important step forward" for ties between Washington and the Syrian opposition.

"We worked hard to make the case that the Free Syrian Army is the sole solution to degrading and defeating ISIS. We have a long road ahead, but the overwhelming support in Congress for our cause is encouraging," Shahbandar told the Reuters news agency from his current base in Istanbul, using an alternative name for "IS."

The US is already engaged in airstrikes against suspected IS targets in Iraq, with similar strikes a possibility in Syria. General Martin E. Dempsey, chairman of the Joint Chiefs of Staff, on Tuesday raised eyebrows by saying that he might recommend the deployment of ground troops in Iraq in the future if airstrikes fail.

Iraq's new Prime Minister, Haider al-Abadi, told the Associated Press news agency that Baghdad did not want US ground forces to return: "Not only is it not necessary; we don't want them. We won't allow them," al-Abadi said. The government in Baghdad, then headed by Nuri al-Maliki, requested international assistance after IS fighters made rapid progress through the north of the country in June.

msh/jr (AFP, AP, dpa)