“Secretary Clinton supports the president’s effort to enlist the Congress in pursuing a strong and targeted response to the Assad regime’s horrific use of chemical weapons,” the aide said.
Clinton is scheduled to appear Monday afternoon at a forum on wildlife trafficking.
She will likely repeat her White House comments during her speech Tuesday night at the National Constitution Center in Philadelphia, the source added.
In addition to pushing for diplomatic efforts to remove al-Assad from power, Clinton backed a proposal last year to provide weapons to Syrian rebels when she served as secretary of state.
Clinton also issued warnings in January shortly before leaving office about Iran’s involvement in Syria, saying the country was providing al-Assad’s regime with military supplies. She urged Iran, as well as Russia, to reconsider their aid to the war-torn country.