WASHINGTON (NYTIMES) - On the last day of August, when United States President Joe Biden called the airlift of refugees from Kabul an "extraordinary success", senior diplomats and military officers in Doha, Qatar, e-mailed out a daily situation report marked "sensitive but unclassified".

The conditions in Doha, according to their description, were getting worse. Almost 15,000 Afghan refugees were packed into airplane hangars and wedding-style tents at al-Udeid airbase, home to the 379th Air Expeditionary Wing and nearby Camp As Sayliyah, a US Army base in the Persian Gulf nation.

Two hundred and twenty-nine unaccompanied children were being held near the base, including many teenage boys who repeatedly bullied younger children. There were a "large number of pregnant women", some of whom needed medical attention, and increasing reports of "gastrointestinal issues" among the refugees.

The reports were daily distillations of the complexity, chaos and humanity behind the largest air evacuation in US history, as scores of diplomats, troops, health workers, security officials and others scattered across the globe sought to rescue tens of thousands of refugees.

Whatever plans the Biden administration had for an orderly evacuation unravelled when Kabul fell in a matter of days, setting off a frenzied, last-minute global mobilisation.

Mr Biden and his aides have insisted that the evacuation of Kabul after the Taliban seized the city on Aug 15 was done as efficiently as possible. But State Department e-mails, documents from the Health and Human Services, Homeland Security and Defence departments, as well as interviews with officials and refugee advocates, suggest otherwise.

Within hours of Mr Biden's speech on Tuesday (Aug 31) at the White House marking the end of America's two-decade war, a private charter plane from Mazar-i-Sharif, Afghanistan's fourth-largest city, arrived at the airbase in Doha - one of 10 way stations in eight countries - with no notice, carrying no US citizens but hundreds of Afghans. The manifest for the plane, apparently chartered by a former Marine's law firm, offered "no clarity" about whether its passengers deserved special visas for helping US troops.

"There are multiple other 'rogue' flights that are seeking the same permissions" to land, e-mails from State Department officials sent that day said. "We have 300 people in Doha now who are basically stateless. Most have no papers."

Administration officials have acknowledged the rough conditions at Doha, but say they are working to improve them. White House officials declined to comment on the record for this article.

The total number of evacuees, and where they are currently waiting, is still not clear, though Mr Biden said on Tuesday that more than 120,000 had been evacuated. As at Friday, Mr Alejandro Mayorkas, secretary of the Department of Homeland Security, said about 40,000 people had arrived in the US at airports near Washington, DC, and Philadelphia. Officials expect about 17,000 more to arrive by next Friday and thousands more may ultimately end up living in a dozen other countries.

US officials have said the refugees are being thoroughly vetted, with the authorities feeding fingerprints, portraits and biographical information into federal databases to weed out potential risks. Mr Mayorkas said the Defence Department had sent hundreds of biometric screening machines to 30 countries.

But unclassified briefing documents titled "2021 Afghanistan Repatriation Mission" reveal that in some cases, spotty information is being collected: Flight manifests have been at times incomplete or missing, visa or citizenship status is unknown, and there is a lack of basic demographic data.

The documents show that the flights into the US started as a trickle. On Aug 19, four days after the Taliban seized control of Kabul, 226 people on two separate flights arrived at Dulles International Airport. Jordan Air JAV 4825 included 44 dogs - but no information about its 58 passengers.

Ten days later, on Sunday, 13 flights landed at Dulles carrying 3,842 people, including six refugees who tested positive for the coronavirus and six unaccompanied boys: four teenagers, one younger school-age boy and one toddler. Flight CMB 581, which landed that day at 6.38pm, carried 240 passengers. But government records provide few details: "about three" US citizens, including two people over 65 and one passenger who tested positive for the virus.

Mr Mayorkas said of the about 40,000 people who had reached the US from Afghanistan, about 22 per cent were US citizens and legal permanent residents and the rest were Afghans, including many who were at risk of retribution at the hands of the Taliban.

The confusion about the refugees began before they left Kabul, as overwhelmed consular officials struggled to identify and verify those who had valid claims to be evacuated.

A senior State Department official who was in Kabul described a desperate situation at the gates around the city's airport and crowds that were so frenzied that officials worried they could slip "into a mob at any given moment".

"Every day was a constant improvisational effort to figure out what was going to work that day," he said. "And I would say, everybody who lived it is haunted by the choices we had to make."

As they raced to evacuate refugees from Kabul, the most critical question facing the Biden administration was: where to put them?

National security adviser Jake Sullivan said the administration had anticipated needing transit centres for an eventual evacuation. But within days of the collapse of the Afghan government, the Pentagon and the State Department rushed to secure more agreements with countries in Europe and the Middle East to allow refugees to be housed temporarily at 10 US bases - officially known as lily pads because the refugees were intended to stay there only a short time.

At the same time, military officials began "Project Allies Welcome", setting up temporary housing at eight military bases in the US.

The question of what will happen over the long term to refugees who arrive in the US is a moving target.

Some have arrived with completed visa applications in recognition of their service alongside the US military. Those people, and their families, will become permanent residents and could earn citizenship.

But the vast majority of the refugees are being granted what is known as "humanitarian parole", which allows them to live in the US for a fixed period, in most cases two years. They may be required to apply for asylum and will get help to find a home in the US while they wait for their cases to be processed.

Officials said they were considering asking Congress to pass legislation that would provide all of the refugees with legal status, much the way lawmakers did for Cubans in the 1960s and Vietnamese refugees in 1975.

As at Thursday, more than 26,100 Afghans fresh off planes had been shuttled to a cavernous room near Dulles, including 3,800 on Wednesday alone. Officials said the arriving evacuees were usually there for less than a day for processing - and in some cases out in an hour or two - surrounded by the sound of crying babies and exhausted-looking people.

During a tour Thursday evening of the hangar-size facility, Secretary of State Antony Blinken was told that many people arrived dehydrated and in need of medical care; several women have given birth since they arrived in the US, including one who had triplets on Wednesday. Additional interpreters have been sent to the centre to make up for a shortage of staff who spoke Dari or Pashto when it first opened Aug 22.

Children ran throughout the maze of hallways between curtained-off rooms where people slept, covered with blue blankets. Seeing three children standing off to one side, Mr Blinken stopped, crouched down and introduced himself.

"Welcome to America, my name is Tony," he said, tapping his chest. "Nice to meet you."