PresidentTrump speaks during a news conference with King Abdullah II of Jordan, not pictured, in the Rose Garden of the White House in Washington, D.C.,  on April 5. (Andrew Harrer/Bloomberg)

Two weeks ago, U.S. officials said that unseating Syrian President Bashar al-Assad was not a priority for the United States. The major focus was defeating the Islamic State,  and the fate of the Syrian president would be “decided by the Syrian people.” Now, U.S. officials are calling for Russia to drop its support of Assad, saying that he is no longer part of Syria's future.

As a presidential candidate, Donald Trump had expressed his desire to go after ISIS in Syria rather than unseating Assad. Yet the chemical attack changed his thinking, as well as the rhetoric on Syria from U.S. officials.

Here's how the chemical strike in Syria not only changed the rhetoric of U.S. officials but also foreign policy:

March 30 — Nikki Haley, U.S. ambassador to the United Nations, says removing Assad from power is no longer a priority, which went against U.S. policy under President Barack Obama and the policy of European allies. “You pick and choose your battles and when we're looking at this, it's about changing up priorities and our priority is no longer to sit there and focus on getting Assad out,” Haley tells a group of reporters. While visiting Turkey, Secretary of State Rex Tillerson says Assad's future “will be decided by the Syrian people.”

March 31 — At a news conference, White House press secretary Sean Spicer clarifies the U.S. policy on Syria, saying the United States was focused on defeating the Islamic State.

April 4 The Syrian military strikes the northwestern town of Khan Sheikhoun in one of the deadliest attacks of the six-year civil war. As many as  58 civilians were killed in the apparent chemical attack, including women and children. Trump blames Assad's alleged use of chemical weapons on Obama's “weakness,” saying: “These heinous actions by the Bashar al-Assad regime are a consequence of the past administration’s weakness and irresolution.”

April 5 — The death toll in the attack rises. Turkish officials say sarin was to blame. At the United Nations, Haley displays photos of dead children and said the United States might consider military actions against the regime, without offering specifics. Tillerson calls Assad's regime “brutal, unabashed barbarism.”

Trump also makes his first significant comments on the strike, saying: “It crossed a lot of lines for me. When you kill innocent children, innocent babies — babies, little babies — with a chemical gas that is so lethal … that crosses many, many lines, beyond a red line.”

April 6 The United States strikes a Syrian airfield in retaliation for the chemical attack. Trump says the strikes were conducted as a “vital national security interest” to the United States to prevent the spread of chemical weapons.

April 7 — Russia condemns the attack. President Vladimir Putin’s spokesman says the strikes are “an aggression against a sovereign government.”

April 9 — Haley and Tillerson double down on their criticisms of Assad and Russia's role in Syria, but they stop short of saying Assad's demise is imminent. “I think the issue of how Bashar al-Assad’s leadership is sustained, or how he departs, is something that we’ll be working [on] with allies and others in the coalition,” Tillerson said during his first appearance on CBS's “Face the Nation.” “But I think with each of those actions, he really undermines his own legitimacy.”  

April 11 — Tillerson, while traveling to Moscow, says Assad's reign “is coming to an end.”

This post has been updated and reformatted.