The Pentagon is in detailed discussions with the White House about military options in Syria.
According to a US official, this could include grounding Syrian aircraft and cruise missile strikes.
President Donald Trump is being briefed on the full range of military options after the White House blamed the Syrian government for the alleged chemical attack in Idlib province earlier this week.
Secretary of State Rex Tillerson said the US was “considering an appropriate response” and added there was “no doubt” President Assad was behind the attack.
He also called on Russia, a key ally of Assad, to reconsider its support for his regime.
Asked if the US will lead a regime change effort in Syria, Tillerson said that “those steps are underway.”
Senators John McCain and Lindsey Graham, who must be rubbing their hands with glee, said Assad “has crossed a line” and “must pay a punitive cost for this horrific attack”.
Among the options would be using cruise missiles to attack Syrian targets and “grounding” Syrian aircraft, an unnamed US official told Reuters on Thursday. The official did not say how likely US military action would be, however.
Secretary of Defense James Mattis and National Security Adviser H.R. McMaster have been discussing the matter, the official said. Mattis is due to meet with Trump later in the day at the president’s Mar-a-Lago retreat, where a summit meeting with Chinese President Xi Jinping is underway.
Speaking with reporters aboard Air Force One, Trump said that “something should happen” with Assad after the chemical attack, calling what happened in Syria “a disgrace to humanity.”
“There is no doubt in our minds, and the information we have supports, that the Syrian regime under the leadership of Bashar al-Assad are responsible for this attack,” Secretary of State Rex Tillerson told reporters in Florida on Thursday, adding that “there is no role for Assad” in Syria after this.
Tillerson also warned Russia that it should “consider carefully their support” for Assad.