President Donald Trump blamed Russia and Iran for backing Syrian dictator Bashar al-Assad after reports emerged Sunday of a chemical weapons attack by the regime against the rebel-held town of Douma on Sunday.

Dozens were reportedly killed in the Saturday attack, though the claims could not yet be independently verified.

Trump named President Vladimir Putin directly — a noteworthy gesture, given his recent insistence on the need to cooperate with Russia, if possible, and the constant complaints of critics still alleging collusion during the election.

Trump tweeted:

Many dead, including women and children, in mindless CHEMICAL attack in Syria. 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… — Donald J. Trump (@realDonaldTrump) April 8, 2018

….to pay. Open area immediately for medical help and verification. Another humanitarian disaster for no reason whatsoever. SICK! — Donald J. Trump (@realDonaldTrump) April 8, 2018

Trump also blamed his predecessor, Barack Obama, for failing to enforce the “red line” on Syria’s chemical weapons that he announced in 2012.

If President Obama had crossed his stated Red Line In The Sand, the Syrian disaster would have ended long ago! Animal Assad would have been history! — Donald J. Trump (@realDonaldTrump) April 8, 2018

The Obama administration took pride in an agreement brokered with Russia, under which all of Assad’s chemical weapons were supposed to have been removed.

Last spring, President Trump responded to a chemical weapons attack on civilians by Syria by attacking a Syrian air force base with nearly 60 Tomahawk missiles. He suggested that a similar response would be necessary if the regime persisted in its use of chemical weapons.

Joel B. Pollak is Senior Editor-at-Large at Breitbart News. He was named to Forward’s 50 “most influential” Jews in 2017. He is the co-author of How Trump Won: The Inside Story of a Revolution, which is available from Regnery. Follow him on Twitter at @joelpollak.