The day of reckoning draws near in Afghanistan as the Taliban’s irresistible advance continues to gain ground and US diplomats prepare to abandon their embassy in Kabul.

The Taliban has seized the last major city outside of Kabul held by the country’s increasingly isolated central government, cutting off the capital to the east.

As helicopters began landing at the US Embassy smoke was seen rising from the grounds as what are believed to be secret files were fed to the flames.

The collapse on Sunday of Jalalabad, near a major border crossing with Pakistan, leaves Afghanistan’s central government in control of just Kabul and seven other provincial capitals out of the country’s 34.

In a nationwide offensive that has taken just over a week, the Taliban has defeated, co-opted or sent Afghan security forces fleeing from wide swathes of the country, even with some air support by the US military.

The rapid shuttle-run flights near the embassy began a few hours later as diplomatic armoured SUVs could be seen leaving the area around the post.

The US government did not immediately acknowledge the movements.

Diplomats were  urgently destroying sensitive documents, according to two American military officials who spoke on condition of anonymity .

President Ashraf Ghani, who spoke to the nation on Saturday for the first time since the offensive began, appears increasingly isolated as well. Warlords he negotiated with just days earlier have surrendered to the Taliban or fled, leaving Ghani without a military option. Ongoing negotiations in Qatar, the site of a Taliban office, also have failed to stop the insurgents’ advance.

Thousands of civilians now live in parks and open spaces in Kabul itself, fearing the future. While Kabul appeared calm Sunday, some ATMs stopped distributing cash as hundreds gathered in front of private banks, trying to withdraw their life savings.

Militants posted photos online early on Sunday showing them in the governor’s office in Jalalabad, the capital of Nangarhar province.

Abrarullah Murad, a lawmaker from the province told The Associated Press that the insurgents seized Jalalabad after elders negotiated the fall of the government there. Murad said there was no fighting as the city surrendered.

Warlords cut and run

The fall on Saturday of Mazar-e-Sharif, the country’s fourth-largest city, which Afghan forces and two powerful former warlords had pledged to defend, handed the insurgents control over all of northern Afghanistan.

In his speech Saturday, Ghani vowed not to give up the achievements of the 20 years since the US-led invasion toppled the Taliban after the 9/11 attacks.

The US has continued holding peace talks between the government and the Taliban in Qatar this week, and the international community has warned that a Taliban government brought about by force would be shunned.

But the insurgents appear to have little interest in making concessions as they rack up victories on the battlefield.

“We have started consultations, inside the government with elders and political leaders, representatives of different levels of the community as well as our international allies,” Ghani said.

“Soon the results will be shared with you,” he added, without elaborating further.

Back to the Dark Ages

Many Afghans fear a return to the Taliban’s oppressive rule. The group had previously governed Afghanistan under a harsh version of Islamic law in which women were forbidden to work or attend school, and could not leave their homes without a male relative accompanying them.

In a statement late Saturday, however, the Taliban insisted their fighters wouldn’t enter people’s homes or interfere with businesses. They also said they would offer an amnesty to those who worked with the Afghan government or foreign forces.

“The Islamic Emirate once again assures all its citizens that it will, as always, protect their life, property and honour and create a peaceful and secure environment for its beloved nation,” the militants said. “In this regard, no one should worry about their life.”

Despite the pledge, those who can afford a ticket have been flocking to Kabul International Airport, the only way out of the country.

-with AAP