The Taliban is rushing to work out how to govern Afghanistan after the militant Islamist group’s exiled leaders came back to a country that has changed profoundly since it was driven from power 20 years ago.

While the Taliban has been setting up shadow governors and administrators to rule its conquered territory, the US has been struggling to repair a bungled evacuation plan for thousands of people trying to flee Kabul.

Washington sent 1,000 more troops to Kabul in an attempt to reassert control over the city’s airport after it was overrun by desperate Afghans and foreign citizens.

Many local residents were reportedly still struggling to reach the airport on Wednesday. Taliban militants have set up checkpoints around the city and were turning back some Afghans.

General Frank McKenzie, commander of US troops in the region, said he had warned Taliban leaders “against interference in our evacuation”.

American citizens in the country were also told that the US government “cannot guarantee” their security as they attempted to make their way to the airport. The US wants to evacuate as many as 9,000 people a day, a big increase from the hundreds being flown out of the country currently.

Zabihullah Mujahid, a Taliban spokesperson who appeared in the group’s first press conference since taking Kabul, said on Tuesday that preparations were under way to form a government.

The militants are trying to consolidate power after seizing control of Afghanistan in just over a week and driving President Ashraf Ghani and most senior government officials into exile.

Abdul Ghani Baradar, the Islamist group’s top political leader, arrived in Afghanistan after two decades on Tuesday, flying into the southern city of Kandahar from Qatar, where he has lived since the US secured his freedom from a Pakistani jail in 2018.

Baradar, who helped negotiate the 2020 deal with Donald Trump’s administration to withdraw US troops from Afghanistan, is expected to take a leading role in an Islamist government in the coming days.

“They have a lot of consolidation to do,” said Rudra Chaudhuri, a senior lecturer at King College London’s Department of War Studies.

“They don’t have a civil service, there is no cadre of administrators,” he said. “They will need parts of the old government to keep this system together and that will require a discussion on transition.”

The group has ordered its fighters not to interfere with the operations of international organisations such as the UN. But was is not clear how much control the political leadership had over fighters on the ground.

“These are people that have not met their own military commanders face-to-face for 10 or 15 years,” Chaudhuri said.

The Taliban insisted its new government would be more moderate than its brutal reign in the 1990s, when the regime erased women’s rights and employed severe punishments for alleged crimes, including public executions and stoning of alleged adulterers.

Mujahid said women’s rights would be respected “within the framework of Islam” and that the group would not seek retribution against former Afghan officials or soldiers.

One Kabul-based security analyst said the Taliban was trying to “build up soft power momentum, versus the hard power of their military thrust and conquering”.

Yet reports from around the country pointed to violence at the hands of victorious Taliban fighters, and many women had been ordered to stay at home.

On Tuesday, a group of more than 40 Democratic and Republican lawmakers called on President Joe Biden to maintain the airlift until all US citizens and Afghan allies had been evacuated.

Chaos at Kabul’s airport had repeatedly halted evacuation flights this week and left at least five dead, with some people falling from the sky after clinging to departing aircraft.

The US Air Force said “human remains” had been discovered in a plane’s wheel well after it landed at Al Udeid Air Base in Qatar.