President Biden promised Friday to bring all Americans home from Afghanistan and portrayed the evacuation effort as one that has made significant progress, despite clear evidence on the ground that the situation was continuing to deteriorate as flights were temporarily delayed and a chaotic scene played out at the gates to the Kabul airport.

During remarks in the East Room of the White House, Biden continued to defend his decision — without acknowledging any errors in the execution of the withdrawal he ordered as he urged Americans to save any criticism for later.

“There will be plenty of time to criticize and second-guess when this operation is over,” Biden said. “But now — now — I’m focused on getting this job done.”

The president vowed in his strongest terms yet that no American would be left behind, and he made the same commitment to Afghans who have aided the U.S. effort over the last two decades.

“Let me be clear: Any American who wants to come home, we will get you home,” he said, before offering significant caveats — saying he didn’t know how many Americans were left or whether they could be brought home safely.

“Make no mistake, this evacuation mission is dangerous. It involves risks to our armed forces,” Biden said. “And it’s being conducted under difficult circumstances. I cannot promise what the final outcome will be.”

The Biden administration scrambled Friday to expand its capacity to evacuate Afghans fleeing the Taliban, adding more bases in the Persian Gulf to the mix after an air base in Qatar reached capacity, stopping military evacuation flights from Kabul for at least six hours.

The adjustment came less than a week after the Taliban seized control of Kabul and as crowds of evacuees inside the capital’s airport swelled to nearly 10,000 people, straining supplies of water and other essentials, U.S. officials familiar with the situation said. Many thousands more waited outside, a short distance from Taliban checkpoints; there were some reports of Americans being beaten by militants despite a promise of safe passage to the airport.

“We’re certainly mindful of these reports, and they’re deeply troubling,” said Pentagon spokesman John Kirby. “We have communicated to the Taliban that that’s absolutely unacceptable.”

At Al Udeid Air Base in Qatar, evacuees waited in hangars in desert conditions with temperatures outdoors exceeding 100 degrees. Maj. Gen. Hank Taylor, a senior official at the Pentagon, told reporters that the military needed to “increase throughput” to send more food, water and other supplies.

“Aircraft availability is not an issue,” Taylor said. “We intend to maximize each plane’s capacity. We’re prioritizing evacuation of people above all else, and we’re focused on doing this as safely as possible, with a great sense of urgency.”

A defense official familiar with the situation said about 5,000 evacuees were in Qatar, with the Air Force beginning to fly some out to other bases to make room for more incoming evacuees. An additional 6,500 evacuees were expected to be sent to military bases in Bahrain and the United Arab Emirates, and other bases in the region could soon be in use, the official said. Air Force officials announced that preparations were underway to receive evacuees at Ramstein Air Base in Germany in the coming days, and defense officials also expect to receive evacuees at bases in Virginia, Wisconsin and Texas.

A second U.S. official familiar with conditions in Qatar expressed exasperation with the situation. He described “row after row after row” of cots crowding aircraft hangars and sanitation concerns including long lines to use too few portable toilets.

“You can’t keep up with the trash,” the official said. “You can’t keep up with the bustle of everyone trying to move. It’s packed.”

Service members at the air base have taken on significant responsibilities, on top of their typical duties, to assist the crowds, volunteering in their free time, the official said. The State Department’s slow processing of evacuees leaves him worried about what’s to come.

“Our slow process is making the crowds worse, and we only have so much time,” the official said. “This cannot go on forever.”

When asked about delays in processing, State Department spokesman Ned Price defended the administration, saying it was left with a large backlog of applicants from the Trump administration caused by chronic understaffing and the coronavirus pandemic.

“As of earlier this month, we were processing more than 800 visas per week,” an increase of eightfold from earlier in the year, Price said. “That was a result of the steps the department took, President Biden took. . . . It is also a function of the support we have from members of Congress.”

In Kabul, sprawling crowds continued to overwhelm streets and passageways near the airport. The Marine Corps acknowledged the accuracy of a video showing an Afghan family passing their infant to a U.S. service member over the top of a concrete wall topped with razor wire.

Maj. James Stenger, a service spokesman, said that the service member who helped was a member of the 24th Marine Expeditionary Unit, from Camp Lejeune, N.C., and that the baby was taken to a medical facility on base for treatment and later returned to the father.

The Biden administration has also been under pressure to expand evacuation efforts beyond the airport after European forces started to cross Taliban lines to rescue civilians. Biden said Friday that he was considering similar moves, saying he would pursue “every means by which we could get folks to the airport.”

The president’s remarks, in which he also took several questions, marked the latest effort by the White House to show that it was attempting to get the situation under control and offered a bookend to one of the most tumultuous weeks of Biden’s presidency.

Biden first delivered remarks about Afghanistan on Monday, and his staff released photos of him meeting with his team. He sat for an interview with George Stephanopoulos of ABC News, and his top advisers publicly and privately repeated that the fall of Kabul last weekend occurred much faster than they, or many others, expected.

On Friday, Biden delayed a planned trip home to Wilmington, Del., and as he spoke his top advisers — Vice President Harris, Secretary of State Antony Blinken, Defense Secretary Lloyd Austin and national security adviser Jake Sullivan — stood stony-faced behind him.

Biden began by saying that “significant progress” had been made since Monday, noting that the airport in Kabul had been secured and that charter flights by civilian and nongovernmental organizations had resumed along with military flights.

But he also acknowledged some of the chaos at the airport.

“We’ve seen gut-wrenching images of panicked people acting out of sheer desperation,” Biden said. “You know, it’s completely understandable. They’re frightened. They’re sad, uncertain what happens next. I don’t think anyone — I don’t think any one of us can see those pictures and not feel that pain on a human level. Now we have a mission, a mission to complete in Afghanistan.”

Biden conceded that there were difficulties outside the airport gates due to the rush of Afghans eager to get out of the country. But despite the reports of deteriorating conditions on the ground, he suggested that Americans should be able to travel through Taliban checkpoints with relative ease and said there was “no indication” that Americans have been unable to get to the airport.

“We’ve made an agreement with the Taliban. Thus far they’ve allowed them to go through,” he said, five weeks after declaring that he did not trust the Taliban. “It’s in their interest for them to go through. So we know of no circumstance where American citizens carrying an American passport are trying to get through to the airport. But we will do whatever needs to be done to see to it they get to the airport.”

He said any attack or disruption in American-led operations would result in a “swift and forceful response.”

Biden on Friday also continued to mount an aggressive defense of his decision to withdraw from Afghanistan — one that he made in April and one that has been fairly popular among Americans, according to most polls.

He insisted that the initial objectives — killing al-Qaeda leader Osama bin Laden and disrupting his terrorist network — were accomplished and that it was no longer worth dedicating troops to fight in the country.

“Does anybody truly believe that I would not have had to put in significantly more American forces?” he asked. “Send your sons, your daughters, like my son was sent to Iraq, to maybe die?”

He said that the terrorist threats that were launched from Afghanistan were not as significant as they once were, and that the United States could disrupt terrorist activities using a far smaller footprint.

“Let’s put this thing in perspective here. What interest do we have in Afghanistan at this point with al-Qaeda gone?” Biden said. “We went to Afghanistan for the express purpose of getting rid of al-Qaeda in Afghanistan as well as getting Osama bin Laden. And we did.”

Kirby, the Defense Department spokesman, clarified later that al-Qaeda still has a presence in Afghanistan, although it is not “significant enough to merit a threat to our homeland, as there was back on 9/11 20 years ago.”

In his remarks, Biden insisted that the withdrawal was not affecting America’s standing among its allies, even though a number of European leaders have expressed deep misgivings about the way the United States has conducted the exit from Afghanistan.

“I have seen no question of our credibility from our allies around the world,” he said. “I’ve spoken with our NATO allies. We’ve spoken with NATO allies — the secretary of state. Our national security adviser’s been in contact with his counterparts throughout the world and our allies.”

NATO Secretary General Jens Stoltenberg said Friday that members would need to ask themselves “hard questions” about the mission in Afghanistan and that he intends to “conduct a thorough assessment of NATO’s engagement.”

Biden said that next week he would participate in a meeting of the Group of Seven nations to coordinate an approach on Afghanistan moving forward, and that he hoped the international community would work to provide humanitarian assistance for refugees crossing into neighboring countries to escape Taliban rule.

The president said in his most definitive terms that he was committed to evacuating Afghans who had helped the United States, saying that like all Americans they would be provided a pathway out of Afghanistan.

He left open the possibility that the United States could extend its Aug. 31 deadline for leaving Afghanistan if not everyone had been evacuated by that point.

“I think we can get it done by then,” he said. “But we’re going to make that judgment as we go.”

One major question is whether the United States should have anticipated how quickly the Taliban could take over the country, including Kabul. The Wall Street Journal reported Thursday that an internal State Department cable, sent July 13 and signed by 23 U.S. Embassy staffers, warned top officials that Kabul could collapse soon after the planned Aug. 31 troop withdrawal deadline.

“I made the decision. The buck stops with me. I took the consensus opinion,” Biden said. “The consensus opinion was that, in fact, it would not occur — if it occurred — until later in the year.”

John Hudson and Karoun Demirjian contributed to this report.