WASHINGTON (AP) — President Joe Biden on Thursday said the U.S. military mission in Afghanistan will conclude on Aug. 31, saying "speed is safety" as the United States seeks to end the nearly 20-year war.

"We did not go to Afghanistan to nation build," Biden said in a speech to update his administration's ongoing efforts to wind down the U.S. war in Afghanistan. "Afghan leaders have to come together and drive toward a future."

Biden also amplified the justification of his decision to end U.S. military operations even as the Taliban make rapid advances in significant swaths of the country.

The effort to further explain his thinking on Afghanistan comes as the administration in recent days has repeatedly sought to frame ending the conflict as a decision that Biden made after concluding it's an "unwinnable war" and one that "does not have a military solution."