"Today's chemical attack in Syria against innocent people, including women and children, is reprehensible and cannot be ignored by the civilized world," Spicer said on Tuesday. "These heinous actions by the Bashar al-Assad regime are a consequence of the past administration's weakness and irresolution."
"President Obama said in 2012 he would establish a red line against the use of chemical weapons and then did nothing," Spicer continued. "The United States stands with our allies across the globe to condemn this intolerable act."
Meanwhile, Secretary of State Rex Tillerson blatantly ignored questions from reporters about the attack.
Tuesday's attack left scores dead in the town of Khan Sheikhoun in Idlib province. According to medical relief organization UOSSM, at least a hundred people were killed and 400 others were injured. It was the worst such attack since 2013.
Syria has repeatedly been under investigation for targeting civilians and opposition forces with chemical weapons. The Syrian government agreed in 2013 to a U.S.-Russian brokered deal to get rid of its chemical weapons stockpile. Tuesday's victims had symptoms that often result from chemical attacks, such as foaming at the mouth. Many of the victims were were women and children, as well as people being treated at a local hospital.
U.S. allies, including British Prime Minister Theresa May, sharply criticized the Syrian government over the attack. May called for an investigation into the incident and said, "If proven, this will be further evidence of the barbarism of the Syrian regime."
Israeli Prime Minister Benjamin Netanyahu said the international community should work "to fully and finally remove these horrible weapons from Syria."
Spicer's comments on Tuesday come after a week of confusion about the Trump's administration's position on Assad's future.
Nikki Haley, the U.S. ambassador to the United Nations, called the Syrian president a "war criminal" who's done "disgusting things to his own people" at a press conference in New York City on Monday. "We have no love for Assad. We've made that very clear," Haley said, according to Reuters.
But Haley's statement came just days after she suggested the U.S. was softening its stance on Assad. "Our priority is no longer to sit there and focus on getting Assad out," she told a group of reporters on Thursday.
UPDATE: 3:40 p.m. ― The AP reported Tuesday afternoon that Tillerson called on Russia and Iran to make sure Assad does not launch chemical weapons attacks.