French Foreign Minister Jean-Marc Ayrault said on Sunday Russia and Iran would become accomplices in war crimes if they continued to prolong the war in Syria.

Describing Russia and Iran as supporters of Syrian President Bashar al-Assad, Ayrault called on them "to take their responsibility by stopping this strategy that leads to a dead-end."

"Otherwise, Russia and Iran will become accomplices of the war crimes committed in Aleppo," the minister said in a written statement with reference to the bombings that struck the Syrian city and killed scores of people.