After reports of a chemical weapons attack in Syria that left at least 40 dead, President Trump warned there will be a “big price to pay.”

In a rare move, Trump slammed Russian President Vladimir Putin for backing Syrian leader Bashar al-Assad and took aim at Iran as well.

“Many dead, including women and children, in mindless CHEMICAL attack in Syria,” Trump said in a post on Twitter. “Area of atrocity is in lockdown and encircled by Syrian Army, making it completely inaccessible to outside world. President Putin, Russia and Iran are responsible for backing Animal Assad. Big price…”

“….to pay,” he continued. “Open area immediately for medical help and verification. Another humanitarian disaster for no reason whatsoever. SICK!”