The Taliban have captured another three provincial capitals in Afghanistan, completing their sweep of the country's south in a lightning offensive that is gradually encircling Kabul, just weeks before the US is set to officially end its two-decade war.
The latest significant blow was the loss of Lashkar Gah, the capital of Helmand province, where Australian, American, British and other coalition forces fought some of the bloodiest battles in the past 20 years.
Hundreds of foreign troops were killed in the province, which is also a major opium hub.
Local politicians also said Uruzgan's capital Tarin Kot, where Australian forces were based during their 20-year deployment, had fallen to the Taliban.
In the country's west, Fazil Haq Ehsan, head of the provincial council in Ghor province, said its capital Feroz Koh also fell to the insurgents.
The insurgents have taken half of the country's 34 provincial capitals in recent days, including its second and third largest cities, Herat and Kandahar.
The Taliban now control more than two-thirds of the country.
While the capital Kabul isn't directly under threat yet, the losses and advances elsewhere further tighten the grip of a resurgent Taliban.
The latest US military intelligence assessment suggests Kabul could come under insurgent pressure within 30 days and that, if current trends hold, the Taliban could gain full control of the country within a few months.
Attaullah Afghan, the head of the provincial council in Helmand, said the Taliban captured Lashkar Gah following weeks of heavy fighting and raised their white flag over governmental buildings.
Two politicians from the southern Uruzgan province, Bismillah Jan Mohammad and Qudratullah Rahimi, confirmed local officials surrendered Tarin Kot to the Taliban on Friday.
Atta Jan Haqbayan, the provincial council chief in Zabul province, said the local capital Qalat fell to the Taliban and that officials were in a nearby army camp preparing to leave.
On Thursday, the Taliban captured Ghazni, situated on the Kandahar to Kabul road some 150 kilometres south-west of the capital.
US sending 3,000 extra soldiers in
The fall of major cities was a sign that Afghans welcomed the Taliban, a spokesperson for the group said, according to Al Jazeera TV.
The US State Department said Secretary of State Antony Blinken and Defence Secretary Lloyd Austin spoke to Afghan President Ashraf Ghani on Thursday and told him the United States "remains invested in the security and stability of Afghanistan".
In response to the Taliban's swift advance, the Pentagon said it would send about 3,000 extra troops within 48 hours to help evacuate embassy staff.
There are thought to be about 1,400 staff remaining, but that will be reduced to a "core diplomatic presence".
Britain said it would deploy around 600 troops to help its nationals and local translators get out.
Canadian special forces will also deploy to Afghanistan and Canadian staff in Kabul will be evacuated before the embassy is closed, a source familiar with the plan told The Associated Press.
Defence Minister Peter Dutton said diplomats were working with Australians in Afghanistan to get them out of the country as soon as possible.
Mr Dutton told Channel Nine there were dozens of Australian civilians in Afghanistan, but couldn't put a timeframe on when they would be evacuated.
Prime Minister Scott Morrison said Australia was "liaising" with the US and other allies to evacuate people.
"We will be working closely with them including, when necessary using Australian Defence Force personnel to assist in securing that outcome," Mr Morrison said.
About 3,500 additional US troops will be sent to the region to be on standby if the situation worsens, as well as 1,000 personnel to Qatar help process Afghans going through a special immigration process.
While it is common for the US military to send in a large number of troops to evacuate personnel in combat zones, the reinforcements will fly in just weeks before the departure of the last of the US-led international force that has had a core role in maintaining security in the country.
The military mission in Afghanistan is set to end on August 31, and roughly 650 troops remain in the country to protect the airport and embassy.
'We are returning to a dark time'
Taliban spokesman Qari Yousuf Ahmadi said the Herat governor's office had been seized, and government forces were surrendering.
"As you can see, we are inside the Herat police headquarters right now," a Taliban fighter said in a video that Ahmadi shared.
In Kandahar, most parts of the city were under the group's control, but fighting was still going on, a Taliban commander told Reuters.
However, AP has reported Afghan officials as saying that the city was already lost.
A women's rights activist there, who asked not to be named for security reasons, said heavy clashes were underway, and only the city's military bases and airport remained under government control.
She felt certain that restrictions imposed on women by the Taliban when the group ruled the country from 1996-2001 would return.
The spiralling violence and the militants' swift advances prompted the United States and Germany to urge their citizens to leave the country immediately.
Saigon comparisons
The speed and violence of the Taliban offensive has sparked recriminations among many Afghans over President Joe Biden's decision to withdraw US troops, 20 years after they ousted in the Taliban in the wake of the September 11 US attacks.
Mr Biden said earlier this week he did not regret his decision, noting Washington had spent more than $US1 trillion in America's longest war and lost thousands of troops.
He added the US continued to provide significant air support, food, equipment and salaries to Afghan forces.
US Senate Republican leader Mitch McConnell said the exit strategy was sending the US "hurtling toward an even worse sequel to the humiliating fall of Saigon in 1975".
"President Biden is finding that the quickest way to end a war is to lose it," Mr McConnell said, urging him instead to commit to providing more support to Afghan forces.
Is diplomacy still an option?
In a deal struck with former US president Donald Trump's administration last year, the insurgents agreed not to attack US-led foreign forces as they withdrew. The Taliban also made a commitment to discuss peace.
Given the speed of the Taliban's advance, prospects for diplomatic pressure to affect the situation on the ground seemed limited, although the Taliban spokesman told Al Jazeera: "We will not close the door to the political track."
Al Jazeera reported a government source saying it had offered the Taliban a share in power if the violence stopped.
Taliban spokesperson Zabihullah Mujahid said he was unaware of any such offer but ruled out sharing power.
The international envoys in Doha, who met with Afghan government negotiators and Taliban representatives, reaffirmed that foreign capitals would not recognise any government in Afghanistan "imposed through the use of military force".
ABC/wires
