Taliban checkpoints around Kabul airport are blocking Afghans from accessing the terminal, making it difficult for the West to evacuate local staff who worked for Western forces, German Foreign Minister Heiko Maas said on Tuesday.

"The Taliban has set up checkpoints everywhere in the city and have the entire area and the airport surroundings in their hands," said Maas at a press conference.

The only people allowed through into the airport are "foreign citizens, but no local workers and no Afghan citizens" are given access, he said.

Germany is in dialogue with the United States on the issue, in the hopes of pressing US representatives who are in discussion with the Taliban in Doha of obtaining safe passage for Afghans to the airport.

Maas said a German diplomat will also be dispatched to Doha to join talks.

Thousands of panicked people fled to the airport in a bid to get on departing Western flights, after the Taliban seized control of the country. 

According to a government report seen by AFP on Tuesday, the situation has calmed down since the Taliban set up security posts around the airport.

This is making it easier for international forces to evacuate their nationals but "the closure of the airport to Afghan nationals is making it more difficult to evacuate former Afghan local staff", the document said.

Speaking in Berlin on Tuesday, Chancellor Angela Merkel said the big question over the next few days would be "above all, how many can reach the airport in Kabul".

Berlin estimates that 2,500 local employees who worked with German troops or at the embassy, as well as their family members, need to be evacuated from the country.

Another 2,000 Afghans, such as human rights activists or employees of non-governmental organisations, also need to be brought out of the country. The number swells to 10,000 if their family members are included.

Officials admitted on Tuesday that a German military plane left Kabul carrying just seven evacuees while hundreds waited on the ground because allies responsible for security at the airport could not secure their access to the aircraft.

However, a second plane left Kabul on Tuesday afternoon with more than 125 people on board, including Germans, Afghans and other nationals, Maas said.

Another 180 people are currently at the airport awaiting evacuation by the German military, the minister added.

This image distributed Courtesy of the US Air Force shows the inside of Reach 871, a U.S. Air Force C-17 Globemaster III flown from Kabul to Qatar on August 15, 2021.

US: no Taliban interference

Meanwhile, the US military said that it was stepping up its evacuation from Afghanistan and that the Taliban were not interrupting operations at the Kabul airport.

Major General Hank Taylor said that US military officials at the airport had been in communication with commanders of Taliban forces in recent days and that they were confident that the removal of thousands of US citizens and Afghans fleeing the country on US military aircraft would continue over the coming days.

"We have had no hostile interactions, no attack and no threat by the Taliban," said Taylor, a senior official with the Pentagon' Joint Chiefs of Staff.

Taylor said that since the airport was reopened early Tuesday following an hours-long closure for security problems, the US military has evacuated close to 800 people, among them 165 Americans, on seven flights.

The US Department of Defense has poured troops into the airport since Saturday to protect the exodus as the Taliban insurgents entered Kabul after a lightning siege across the country and seized power.

Taylor said the number of US troops would rise from 2,500 on Monday to around 4,000 by late Tuesday.

He said the US aimed to increase its airlift to one aircraft an hour so that between 5,000 and 9,000 passengers could be carried out per day.

"We are confident we have taken the right steps to resume safe and orderly operations at the airport," he said.

Some other countries, including Germany and France, have also been able to land aircraft to pick up their nationals and Afghans qualified to travel to those countries.

Taylor spoke a day after security broke down at the airport, with videos showing hundreds of Afghans on the runway trying to impede a giant C-17 transport and clinging to it.

Videos appeared to show two people falling to their deaths from the aircraft after it took off.

Another, according to the Washington Post, was later found dead in a wheel well.

Pentagon spokesman John Kirby said those incidents were being looked into by the US Air Force.

Taylor did not provide any figures on how many people, US citizens or other nationals, or Afghan citizens, were currently in the airport seeking to leave.

The United States has pledged to accept tens of thousands of people such as translators who worked for US forces and their families, as they fear retribution from the Taliban.

More than a thousand have been evacuated since the operations began three days ago.