President Joe Biden says the US military operation in Afghanistan will end on 31 August, even as he bluntly acknowledged there will be no “mission accomplished” moment to celebrate.

Biden pushed back against the notion the US mission has failed but also noted that it remains unlikely the government would control all of Afghanistan after the US leaves.

He urged the Afghan government and Taliban, which he said remains as formidable as it did before the start of the war, to come to a peace agreement.

“We did not go to Afghanistan to nation build,” Biden said in a Thursday speech from the White House’s East Room.

“Afghan leaders have to come together and drive toward a future.”

On Thursday he amplified the justification of his decision even as the Taliban make rapid advances in significant swaths of the country.

“How many more, how many more thousands of American daughters and sons are you willing to risk?” Biden said to those calling for the US to extend the military operation.

He added, “I will not send another generation of Americans to war in Afghanistan, with no reasonable expectation of achieving a different outcome.”

With U.S. and NATO ally forces rapidly drawing down in the past week, there was growing speculation that U.S. combat operations have already effectively ended.

But by setting 31 August as the drawdown date, the administration nodded to the reality that the long war is in its final phase, while providing itself some cushion to deal with outstanding matters.

The administration has yet to complete talks with Turkey on an arrangement for maintaining security at the Kabul airport and is still ironing out details for the potential evacuation of thousands of Afghans who assisted the US military operation.

“The Taliban would have again begun to target our forces,” Biden said. “Staying meant U.S. troops taking casualties. American men and women. Back in the middle of a civil war.”

“The mission was accomplished in that we got Osama bin Laden and terrorism is not emanating from that part of the world,” he said.

U.S. forces this week vacated Bagram Airfield – the U.S. epicenter of the conflict to oust the Taliban and hunt down the al-Qaida perpetrators of the 2001 terrorist attacks that triggered the war.

Biden, answering questions from reporters after his remarks on Thursday, said that Kabul falling to the Taliban would not be an acceptable outcome.

“Do I trust the Taliban? No,” Biden said. “But I trust the capacity of the Afghan military, who is better trained, better equipped and more competent in terms of conducting war.”

To be certain, the West hopes Taliban gains will be confined mostly to rural areas, with the Afghan government and its allies retaining control of the cities where much of Afghanistan’s population resides.

Asked by a reporter whether rampant corruption within the Afghan government has plague stability, Biden didn’t exactly dismiss the notion. “The mission hasn’t failed – yet.”

“The Taliban is gaining more ground by the day, and there are targets on the backs of our people and our partners,” said Rep. Michael McCaul of Texas, the top Republican on the House Foreign Affairs Committee.

“But rather than taking the opportunity to reassure the American people there are sufficient plans in place to keep American diplomats and our Afghan partners safe, President Biden only offered more empty promises and no detailed plan of action.”

“We went for two reasons: one, to bring Osama bin Laden to the gates of hell, as I said at the time,” Biden said. “The second reason was to eliminate al-Qaida’s capacity to deal with more attacks on the United States from that territory. We accomplished both of those objectives. Period.

“That’s why I believe this is the right decision and quite frankly overdue.”