National Security Adviser Lt. Gen. H.R. McMaster on Sunday left open the possibility that President Trump will take further military action in Syria, but made clear the president wants a “political solution” to the Syrian crisis.

“We need to do everything we can,” McMaster said on "Fox News Sunday." “We need some kind of political solution to that very complex problem.”

He spoke several days after Trump authorized the U.S. military to fire 59 missiles on an airbase in central Syria, in response to Syrian President Bashar Assad launching another chemical weapons attack that killed dozens of civilians, including children.

McMaster also made clear that Trump wants a worldwide response to Assad’s action that would include Assad allies Russia and Iran.

“I’m not saying we are the ones to effect that change,” he said. Russia and Iran “somehow think it’s OK to align with a murderous regime.”

He also said Sunday that the administration will try to simultaneously change the Assad regime and destroy the Islamic State terror group, entrenched in Syria, in an attempt to clarify Trump’s foreign policy.

“There has to be a degree of simultaneous action with some sequencing,” McMaster said.

He also argued the overarching message is that Trump responded to Assad’s aggression against civilians when former President Barack Obama failed to make good on such a promise in 2013.

“This is the first time that the U.S. has acted to the atrocities of the Assad regime,” he said. “The president will make whatever decision he thinks that is best for the American people.”