Sen. John McCain on Sunday connected President Trump talking about withdrawing the U.S. military from Syria with a suspected chemical attack.

"President Trump last week signaled to the world that the United States would prematurely withdraw from Syria," McCain said in a statement. "Bashar Assad and his Russian and Iranian backers have heard him, and emboldened by American inaction, Assad has reportedly launched another chemical attack against innocent men, women and children, this time in Douma."

The Arizona Republican, who chairs the Senate Armed Services Committee, urged Trump to take military action similar to that taken a year ago.

"The President responded decisively when Assad used chemical weapons last year," McCain said. "He should do so again, and demonstrate that Assad will pay a price for his war crimes."

The United Nations Security Council is expected to meet on Monday in response to a reported chemical attack in Syria, which activist groups say killed at least 42 civilians in the rebel-held city of Douma on Saturday.

Trump took to Twitter to blame Russia, Iran and “Animal Assad” — a nickname for Syrian president Bashar Assad — for the attack, and said there will be a “big price to pay.”

On April 4, 2017, a chemical attack on the Syrian city of Khan Shaykhun killed at least 74 people and injured more than 55 — the deadliest use of chemical weapons in the Syrian civil war since 2013 in Ghouta.

In response, the U.S. dropped 59 Tomahawk cruise missiles on the Al Shayrat airfield.

Responding to the 2017 attack, McCain said the Trump administration was “partially to blame,” and called on the administration to have a more concrete strategy to deal with Syria.

"We can and should change course — starting with a comprehensive strategy that lays out clear objectives for our mission there. It's not too late to stop Assad's impunity and begin to rewrite this terrible chapter in our history," McCain said Sunday.

Earlier Sunday, Sen. Lindsey Graham, R-S.C., said called Trump’s response to the latest attack "a defining moment.”

“You need to follow through with that tweet,” he said. “Show a resolve that Obama never did to get this right.”