President Biden spoke on Monday and defended the decision to move forward with the withdrawal of U.S. troops from Afghanistan. President Biden’s remarks came after a chaotic day at the Kabul airport as evacuations were halted for several hours. Pentagon spokesman John Kirby confirmed that U.S. troops had killed two armed Afghans who were part of the huge crowd that breached the airport perimeter.

In remarks from the East Room of the White House, Biden said: “How many more generations of America’s daughters and sons would you have me send to fight Afghanistan’s civil war when Afghan troops will not? How many more lives, American lives, is it worth, how many endless rows of headstones at Arlington National Cemetery?” While Biden conceded the Taliban had taken over more quickly than anticipated, but he insisted “there was never a good time to withdraw.”

The Taliban took control of the capital, Kabul, on Sunday, with the U.S. military holding on to the airport for evacuations. The U.S. is continuing to process visas for Afghans and their families who aided U.S. troops. Roughly 100 U.S. embassy staffers remain at the airport —they will be the last ones out.