A U.S. airstrike killed Iranian General Qasem Soleimani, head of Iran's elite Quds Force, at Baghdad's International Airport early Friday. 

The assassination, directly ordered by U.S. President Donald Trump, was celebrated by his administration but received condemnation from countries and protesters in the Middle East. 

Leaders and politicians from other countries are appealing for calm and a lessening of U.S.–Iran tensions. Here's what has been said.