Biden makes his case on U.S. withdrawal from Afghanistan as the Taliban gain ground.

David E. Sanger and 

The New York Times

President Joe Biden delivered remarks on continued drawdown efforts in Afghanistan at the White House on Thursday.
Credit…Sarahbeth Maney/The New York Times

President Biden made an impassioned case on Thursday that the United States could no longer afford the human cost or strategic distraction of fighting the war in Afghanistan, arguing that the United States had achieved its initial objective — routing Al Qaeda from the country and hunting down Osama bin Laden — and that Afghanistan’s government and forces must be responsible for their own future.

He said all American combat troops would be out of the country by Aug. 31, and said the American drawdown “is proceeding in a secure and orderly way prioritizing the safety of our troops as they depart.”

“We did not go to Afghanistan to nation-build,” Mr. Biden said from the East Room of the White House. “And it’s the right and the responsibility of Afghan people alone to decide their future and how they want to run their country.”

Mr. Biden’s speech, just days after the U.S. pulled out of Bagram Air Base, which was the operations center of the 20-year war, marked his formal acknowledgment that the U.S. could not alter the country’s course.

“No nation has ever unified Afghanistan, no nation. Empires have gone there and not done it,’’ he said in a reference to the British occupation of the country in the 19th century and the Soviet effort to gain control three decades ago. Both efforts failed, and Mr. Biden was, in essence, adding the United States to the list.

“I will not send another generation of Americans to war in Afghanistan with no reasonable expectation of achieving a different outcome,’’ Mr. Biden said. But in answering questions from reporters after his prepared remarks, he also rejected the contention that American intelligence had concluded that Kabul, the capital, could fall, and said it would not be comparable to what happened in Saigon in 1975, when the North Vietnamese took over the south.

“There is going to be no circumstance in which you are going to see people being lifted off the roof of an embassy of the United States from Afghanistan,’’ Mr. Biden contended. At another point he added: “I trust the capacity of the Afghan military.”

The departure of American troops has been accompanied by reports of increasingly dire situations on the ground as local government forces crumble before the Taliban, which is gaining territory as it nears Kabul. In the span of just over two months, the Taliban have managed to seize at least 150 of Afghanistan’s 421 districts.

Mr. Biden seemed to acknowledge that reality when he said to reporters, “The mission hasn’t failed — yet.”

In an interview on Fox News on Wednesday, John Kirby, the Pentagon spokesman, said that the Biden administration continued to “push for a negotiated peaceful, political settlement,” while adding that the Pentagon still had the ability to support Afghan forces even without a formal presence in the country.

“We are all concerned about the security situation the ground,” Mr. Kirby said. “There’s no question about that.”

Only 650 troops are expected to remain in the country to protect the U.S. Embassy in Kabul and Kabul International Airport. But officials have said that the Pentagon would be authorized, at least through September, to move 300 additional troops into Afghanistan if needed for security or emergencies.

Air support for the Afghan forces and overhead surveillance can also be flown in from American bases in Qatar or the United Arab Emirates, or from an aircraft carrier in the Arabian Sea. But it is unclear how long the United States will maintain that type of support.

As the Taliban consolidates power in Afghanistan, the threat to American allies who remain in the country grows. Senior officials have said that the Biden administration is preparing to relocate thousands of Afghan interpreters, drivers and others who worked with American forces to other countries in an effort to keep them safe while they apply for entry to the United States.

In his remarks, Mr. Biden also touched on plans for humanitarian assistance to Afghanistan, an issue that came up last week when Afghanistan’s president, Ashraf Ghani, visited the White House. The Biden administration has committed $266 million in humanitarian aid and $3.3 billion in security assistance. It has also pledged three million doses of the Johnson & Johnson vaccine and oxygen supplies, as efforts to address the latest wave of the coronavirus have been hampered by fighting in the area.

“I stressed in my meeting just two weeks ago with President Ghani and Chairman Abdullah, Afghan leaders have to come together and drive toward a future that the Afghan people want and they deserve,” Mr. Biden said in his remarks.

Biden makes his case on U.S. withdrawal from Afghanistan as the Taliban gain ground.