Sen. John McCain said Tuesday that the lack of a more aggressive policy from the Trump administration on Syria is contributing to violence there, along the lines of what was seen under the Obama administration.

"We've seen this movie before when Barack Obama said we would have a red line, they crossed it and we did nothing," McCain said, "Bashar al-Assad and his friends, the Russians, take note of what the Americans say … and I'm sure they took note of what the secretary of state said."

"I'm sure they're encouraged and know the United States is withdrawing," he added.

McCain spoke after reports that 58 people were killed in the attack on Khan Shikhun in Idlib province. According to the report, planes carrying weapons laced with unidentified chemicals raided the city and victims showed symptoms similar to those caused by sarin gas exposure.

The attack comes days after the Trump administration went public with its policy that it would allow Syrian President Bashar Assad to stay in office in order to find an end to the conflict. McCain said comments by Secretary of State Rex Tillersson's comment that the Syrian people should make their own choices for their future empowered the Syrians and their allies, Iran and Russia, to possibly drop chemical weapons on their people.

McCain argued that there's no clear direction coming from the Trump administration on what its policy in Syria will be, aside from a seeming willingness to kowtow to Russia and Assad. Failure to push for Assad's removal from office and the end of his regime is a failure of American ideals, he said.

"It's another disgraceful chapter in American history," he said.

McCain said Trump should change the track of American involvement in Syria to arm the Free Syrian Army, remove Assad and punish Russia for its role in backing the regime. He's hoping the people around Trump will push him in the right direction.

"I don't see any doctrine right now," he said. "I do have great confidence in the national security team around the president … and I hope that they will develop a strategy, stand up and give the president the advice and counsel I believe he needs and can get from that team."