John Kerry 'absolutely certain' Syria using chemical weapons on civilians

WASHINGTON, June 16 (UPI) -- Secretary of State John Kerry said Tuesday he's "absolutely certain" that Syrian President Bashar Assad's regime has used chemical weapons against civilians.

Since the beginning of Syria's civil war in 2011, there have been a number of accusations that Assad has employed the use of gas chemicals against rebels and civilians. Most recently, Human Rights Watch said it found evidence the government used chemical weapons in the Idlib governate in attacks spanning two weeks in March.

The government has consistently denied the allegations, but Kerry said he believes the reports to be true.

"I am absolutely certain -- we are certain -- that the preponderance of those attacks have been carried out by the regime, and we're putting together a portfolio of that data that supports that," he said Tuesday during the State Department's daily briefing. "But that is not to say that some element of an opposition may not have had access at one point in time or another and have actually utilized something at one point in time or another.

But the chemicals have been largely dropped from airplanes, Kerry said, and the opposition doesn't have access to airplanes or helicopters.

"So it's frankly not that hard to pin down in the end, and that's some of what we will lay out at the appropriate time," Kerry said.

He said the United States is involved in a number of diplomatic efforts to halt the use of chemical weapons in Syria.

"I think everybody's patience is wearing thin with respect to the extraordinary depravity of the weaponry and mechanisms for delivery, which Assad has used against his own people," Kerry said. "Thus far, it has not been stopped, and I think it is only increasing the international community's anger at the Assad regime."