The White House has concluded with "high confidence" that the Syrian regime has used chemical weapons against the opposition forces, causing the deaths of at least 100 to 150 people, a senior official said.
"Following a deliberative review, our intelligence community assesses that the Assad regime has used chemical weapons, including the nerve agent sarin, on a small scale against the opposition multiple times in the last year," Deputy National Security Advisor Ben Rhodes said in a statement. "Our intelligence community has high confidence in that assessment given multiple, independent streams of information."
In a conference call with reporters, Rhodes said Syria's action "violates international norms and crosses red lines that have existed in the international community for decades."
He said the U.S. will provide more assistance to the Syrian opposition — including military support — but that "we are going to make decisions about further actions on our own timeline."
Rhodes said he could not provide the details of they types of support to the rebels, but that the "scale and scope" would be stepped up with the aim of "strengthening the effectiveness of the SMC [opposition] on the ground."
Later, Rhodes mentioned the possibility of providing communications equipment and medical equipment and supplies to the opposition.
"We are also going to be consulting with Congress in the days ahead and with the international community," Rhodes said.
In April, President Obama said that the U.S. had physiological evidence that sarin nerve gas had been used in Syria.
Arizona Sen. John McCain, speaking on the Senate floor Thursday, said that the decision to provide arms to the Syrian opposition "is not enough."
McCain has also called for imposing a no-fly zone over Syria and for airstrikes to "take out Assad's air assets."
Rhodes said "there are huge costs" associated with a no-fly zone, that it would be difficult to implement and that there's no guarantee it would substantively change the situation on the ground.