Taliban fighters carrying out a blitzkrieg-like offensive across Afghanistan appear to have the capital, Kabul, in their sights, advancing toward the city even as the first of thousands of U.S. troops to be sent back to the country set foot on the ground.
The Taliban seized control of Asadabad, capital of eastern province of Kunar, Saturday afternoon, which brings to 20 the number of provincial capitals that have fallen to the insurgents over the past week or so, Taliban and area residents confirmed.
The Taliban claimed victory Friday in five major provincial capitals, including the country's second- and third-largest cities, Kandahar in the south and Herat in the west.
A day earlier, the group captured Ghazni, a key city on the road from Kandahar to Kabul and just 150 kilometers from the Afghan capital, setting off a new round of concern in Washington over the rapidly deteriorating security situation
"You can see that they are trying to isolate Kabul," Pentagon press secretary John Kirby warned reporters Friday, cautioning that the city "is not right now in an imminent threat environment."
Still, he called the speed of the Taliban's advance "deeply concerning."
"What they want to do if they achieve that isolation, I think only they (the Taliban) can speak to," he added. "It is not unlike the way they've operated in other places of the country — isolating provincial capitals and sometimes being able to force a surrender without necessarily much bloodshed."
Others seemed resigned to accepting that Kabul could fall, barring significant changes.
"Obviously not on a great trajectory," said one official speaking to VOA on the condition of anonymity because of the sensitive nature of the intelligence.
"The gains the Taliban have made have increased their combat capability, and I think it has certainly challenged the morale and the capability of the Afghan forces," the official added.
But there are questions about how willing the Taliban will be to move on the capital and risk running into some of the 3,000 U.S. troops charged with providing security for U.S. personnel and the nearby Hamid Karzai International Airport.
The Pentagon said that the first of those forces, from a Marine infantry battalion, arrived on Friday and that the rest of the troops were expected to be in place by the end of Sunday.
Their task will be to help evacuate all nonessential personnel from the U.S. embassy, as well as thousands of Afghans and their families eligible for special immigrant visas, a mission military commanders expect could put the troops in harm's way.
"They will have the right of self-defense. They will be armed," the Pentagon's Kirby told reporters.
"Any attack on our forces in Afghanistan will be met swiftly with a forceful and an appropriate response," he said.
In addition, U.S. officials warned that any attempted attack on U.S. forces would have to contend with U.S. airstrikes, not only from bombers and drones flying from U.S. bases in Qatar or aircraft carriers in the Persian Gulf, but also from helicopters stationed at the airport.
Officials have also voiced support for the remaining Afghan security forces: those who continue to provide security for most of Kabul and for the airport's outer perimeter and those still battling Taliban fighters elsewhere in the country.
Kirby said Friday there was still a chance they could "turn the tide" against the Taliban offensive.
"The Afghans have the capability to do that," he said. "We still believe that they could make a difference on the ground."
Taliban spokesman Zabihullah Mujahid warned that the Taliban were determined to push ahead with their offensives to take control of all the provinces, and he urged Afghan security forces in the remaining areas to "end resistance and not risk your lives."
Despite the withdrawal of U.S. and other Western troops, NATO Secretary General Jens Stoltenberg said Friday the alliance "will maintain our diplomatic presence in Kabul and continue to adjust as necessary."
"Our aim remains to support the Afghan government and security forces as much as possible," Stoltenberg added.
Ayaz Gul contributed to this report from Islamabad.