Intelligence agencies estimate that 100 to 150 people have died as a result of chemical weapons use, he said.
Rhodes did not detail what he called the expanded military support, but it is expected initially to consist of light arms and ammunition. He said the shipments would be “responsive to the needs” expressed by the rebel command.
Obama has “not made any decision” to pursue a military option such as a no-fly zone and has ruled out the deployment of U.S. ground troops, Rhodes said.
Syria’s outgunned rebels have issued urgent appeals this week for antitank and antiaircraft weaponry to counter a government offensive that is backed by Hezbollah fighters and Iranian militia forces.
“Suffice it to say this is going to be different in both scope and scale,” Rhodes said of the new assistance. Obama said last year that confirmation of chemical weapons use would cross a “red line” for the United States.
The shipments, to begin in a matter of weeks, will be undertaken by the CIA. The agency has been the primary U.S. government interlocutor with the opposition’s Supreme Military Council, led by Gen. Salim Idriss. Such covert action requires a signed presidential finding.
That method avoids what the administration previously has said are legal restraints on supplying arms for attacks against another government without approval by an international body such as the United Nations, according to U.S. officials who spoke on the condition of anonymity about intelligence matters.
The weapons would probably be delivered by air to Turkey or Jordan, or both, and by land into Syria along rebel-held corridors. The opposition’s requests for antitank and antiaircraft weaponry are still under discussion.
The CIA declined to comment on the new direction in Syria policy.
Despite its long insistence that Syrian President Bashar al-Assad must leave power and its recognition of the opposition as “a legitimate representative of the Syrian people,” the United States and most of the world still officially recognize the Assad government.
Rhodes said the administration would continue to push for a negotiated political settlement of the conflict, including a proposed conference between opposition leaders and government representatives that is on hold.
Syria will be at the top of the agenda when Obama meets with leaders of the Group of Eight industrial nations, including Russia, in Northern Ireland next week. Russia, Assad’s primary arms supplier and diplomatic backer, has blocked harsher international action against him at the United Nations.