Victims of the chemical weapons attack lie on the ground in Khan Sheikhoun, in the northern province of Idlib, Syria, April 4, 2017.
White House National Security Adviser H.R. McMaster said Syria's "sponsors", Russian Federation and Iran, were enabling President Bashar al-Assad's "campaign of mass murder against his own civilians".
While former U.S. president Obama chose not to intervene militarily following Assad's use of chemical weapons in 2013, his administration sought the elimination of all chemical weapons in the country.
U.S. President Donald Trump and British Prime Minister Theresa May had agreed to press Russian Federation to distance itself from Assad following the chemical attack by imposing targeted sanctions, but Germany and Italy, both leading G-7 nations, disagreed.
But instead of regime change, what we should focus on is humanitarian relief ...
The terrorists have access to the chemical weapons and the US missile attacks will lead to use of such weapons again, the Iranian president predicted. "The president will make whatever decision he thinks is in the best interest of the American people".
The chemical attack prompted a world outcry and a US missile attack that marked a turning point in the Trump administration's approach to the seven-year-old conflict.
He also "raised eyebrows" on the Meet The Press set when called out Assad for flying bombing runs from the same air base the USA attacked hours earlier. "Assad signed the chemical weapons treaty ban".
Syria's President Bashar al-Assad is interviewed February 10, 2017, in Syria. But in a television interview that aired Sunday, Tillerson said the priority "really hasn't changed".
Secretary of State Rex Tillerson, who is visiting Moscow this week to meet with his Russian counterparts, said Sunday he plans to ask them about their commitment to ensuring Syria has no chemical weapons. A week ago, Haley and Tillerson said that the United States was not working towards unseating Assad, and that such a decision should be up to the Syrian people.
"From now on we will respond with force to any aggressor or any breach of red lines from whoever it is and America knows our ability to respond well", said the statement published by the group on media outlet Ilam al Harbi (War Media).
Iran has provided crucial military and economic assistance to Assad throughout Syria's six-year civil war.
Their comments came as Tillerson was making the Trump administration's first official trip this week to Russian Federation, a staunch Assad ally. "If you look at his actions, if you look at his situation, it's going to be hard to see a government that's peaceful and stable with Assad".