"Our position on MANPADS has not changed. We would have very deep concern about that kind of weaponry getting into Syria," Toner told reporters on Tuesday. "We're not providing any kind of MANPADS."
Earlier in the day, Russian Foreign Minister Sergey Lavrov in phone talks with US Secretary of State John Kerry warned that US arms deliveries to opposition armed groups in Syria could lead to new bloodshed in the war-torn country.
Since 2011, Syria has been engulfed in a civil war, following the protests that had turned violent, as part of the so-called Arab Spring.
On December 17, Russian President Vladimir Putin and his Turkish counterpart Recep Tayyip Erdogan discussed the possibility of a meeting between the Syrian conflicting parties in Astana.
UN Special Envoy for Syria Staffan de Mistura has said the Astana talks will be useful. He also intends to convene negotiations between the Syrian government and opposition in Geneva on February 8.