Australia on Tuesday abruptly announced it will close its embassy in Afghanistan this week, expressing fears over the “increasingly uncertain security environment” in Kabul in the wake of the US decision to withdraw its troops from the war-torn country.

The surprise decision comes a month after Prime Minister Scott Morrison announced the pullout of Australia’s 80 soldiers deployed as part of the NATO’s Resolute Support mission, which is involved in training and assisting the Afghan forces. The country ended its combat mission in 2013.

On Tuesday, the Australian prime minister said the facility would close as an “interim measure” on May 28 – in just three days – “in light of the imminent international military withdrawal from Afghanistan”.

The United States and allied forces have begun withdrawing troops from Afghanistan, 20 years after they toppled the then Taliban regime in a military invasion in the wake of the September 11 attacks on US soil.

The Taliban on Tuesday pledged to provide a “safe environment” to foreign diplomats after Australia announced it would shutter its embassy over security concerns.

“The Islamic Emirate of Afghanistan assures all foreign diplomats and staff of humanitarian organisations that [we] will not pose any threats to them,” Taliban spokesman Mohammad Naeem told AFP news agency. “We will provide a safe environment for their activities.”

The Taliban, which waged an armed rebellion against the US-led NATO troops, has emerged as a strong force controlling many parts of the country. The US withdrawal is part of an agreement Washington signed last year with the Taliban to end the war.

The elected government in Kabul and the Afghan security services remain fragile despite two decades of foreign support, and their success is far from clear without full-scale US backing.

In recent days, violence in the country has soared and Afghan forces have clashed with Taliban fighters not far to the east of Kabul.

The rebels have also seized positions 40km (24 miles) to the west of the city, a traditional gateway to reach the capital and launch deadly attacks.

US troops withdrawal

All US troops are expected to leave by September 11, the 20th anniversary of the 9/11 attacks. The US invaded the country after accusing the then Taliban rulers of harbouring al-Qaeda leaders, including Osama bin Laden, blamed for the deadliest attack on US soil.

Since it joined the NATO-led forces in Afghanistan in 2001, more than 25,000 Australian troops have served in the country over the years, costing the country billions of dollars.

Australian troops were accused of committing abuse against Afghan civilians. Last year a government inquiry found evidence of war crimes against its soldiers. It sacked 13 special forces soldiers for killing unarmed men and children.

Morrison said there was an “increasingly uncertain security environment” without the 80-member Australian contingent and the larger US force as back-up. “The government has been advised that security arrangements could not be provided to support our ongoing diplomatic presence,” he said in a statement.

It was not clear whether there was a specific threat made against the embassy.

Australian officials are still expected to visit Afghanistan from overseas posts, with Morrison saying his country remains “committed to the bilateral relationship”.

“It is Australia’s expectation that this measure will be temporary and that we will resume a permanent presence in Kabul once circumstances permit,” Morrison said.

The sudden closure surprised some experts in Australia.

“It’s a bit of a shocking decision,” said professor of international security at the Australian National University John Blaxland.

“I can understand on one level why they would want to close, but I think it’s a sad indictment that we should walk away like that after 20 years of investment, blood, sweat and tears,” Blaxland told AFP news agency.

“This is not Saigon 1975,” he added, a reference to the dramatic rooftop helipad evacuation of the US embassy in South Vietnam as the Viet Cong and regular communist military forces seized the city.

Blaxland expressed fears that Afghans who work with the Australian government may now be unable to leave.

“That is something that, if we do not address, the shame of that will linger for years,” he said.