In a defiant speech Tuesday, President Joe Biden defended his decision to stick to this week’s deadline to end America’s longest war and pull troops from Afghanistan after nearly two decades.

“I was not going to extend this forever war, and I was not going to extend a forever exit,” he said in a nearly 30-minute address from the White House. “We succeeded in what we set out to do in Afghanistan over a decade ago. It was time to end this war.”

Biden, who has long been a critic of the continued military presence in Afghanistan, has faced backlash as chaotic scenes unfolded at the airport in Kabul. He didn’t directly address the people of Afghanistan who are being left under Taliban rule and without the supportive cover of American military forces.

“If you’re 20 years old today, you’ve never known an America at peace,” he said. “As we close 20 years of war and strife and pain and sacrifice, it’s time to look to the future and not the past.”

He indirectly acknowledged his U.S. critics, repeatedly referring to his predecessor in the White House without naming former President Donald Trump, blaming deals “the previous administration” made for the outcome of the military withdrawal two weeks ahead of the 20th anniversary of the September 11 terrorist attacks.

“Let me be clear, leaving by August 31 was not due to an arbitrary deadline—it was designed to save American lives,” Biden said. “By the time I took office, the Taliban was in its strongest military position since 2001.”

Biden has spent weeks defending plans to end the war in Afghanistan by highlighting what he has described as a lack of a major national security threat from Afghanistan, and promising to shift the nation’s foreign policy focus to countries more likely to host terrorists who could launch an attack on the United States.

But the Islamic-hardline Taliban quickly toppled the Afghan government, after the country’s American-trained military retreated.