Sen. John McCainJohn Sidney McCainMulvaney aims to cement CFPB legacy by ensuring successor's confirmation Trump mocks McCain at Nevada rally Don’t disrespect McCain by torpedoing his clean National Defense Authorization Act MORE (R-Ariz.) said President Obama must hold Syrian President Bashar Assad accountable for his “barbaric” acts amid reports that he is still using chemical weapons against his own people.

“The allegations that President Bashar al-Assad’s forces have again used chemical weapons against the Syrian people in recent attacks are deeply disturbing, but not surprising," McCain said Monday. "It is essential that the Obama Administration work with the international community to fully and immediately investigate these reports.”

McCain’s comments came after reports that a toxic industrial chemical was used in Syria this month, possibly by the Assad regime against a group of rebels.

McCain said, if the reports are substantiated, it would mean Syria violated the terms of its agreement with the United States, and there must be consequences for those actions.

“Whether by chemical weapons attacks or other barbaric means including barrel bombing and starvation campaigns, the Assad regime continues to carry out war crimes in its slaughter of innocent men, women, and children,” McCain said. “Its breach of the chemical weapons agreement should surprise no one, and unless the Obama administration is willing to force a price for such behavior, we should only expect more atrocities to come.”

McCain has been a harsh critic of the way Obama has handled the Syrian civil war, which has resulted in more than 100,000 deaths since it started in 2011. McCain says the United States should be doing more to protect the people of Syria fighting against their dictator.