Afghan President Ashraf Ghani flew to Mazar-i-Sharif to rally pro-government forces as Taliban militants approached northern cities.
The Mazar-i-Sharif has long been an anti-Taliban fortress, and its collapse will be devastating to the government.
In nearby Kunduz, hundreds of government soldiers surrendered to militants at the city’s airport.
Armed groups currently control nine of the country’s 34 state capitals and seize three of them within 24 hours.
US President Joe Biden said he did not regret withdrawing troops from Afghanistan 20 years later on Tuesday, urging Afghan leaders to unite and “fight for their country.”
He claimed that the United States kept its promises to Afghanistan, including providing close air support, paying military salaries, and supplying government troops with equipment and food.
US-led military operations began in 2001 following the 9/11 attacks on US soil, but most foreign troops are now withdrawing.
On Wednesday, President Gani negotiated a crisis in Mazar-i-Sharif with Uzbek warlord Abdul Rashid Dostam and prominent Tajik leader Atta Muhammad Noor on the defense of the city.
Veteran commander Dostam reportedly said, “The Taliban have come north several times, but they have always been trapped.”
For years, Mr. Gani tried to put the warlords aside to boost the Afghan army, and now he relies on them when he needs them, says BBC Etilajan Ambarasan. .. Earlier this week, the president also agreed to arm pro-government militias.
Mazar-i-Sharif is near the border between Uzbekistan and Tajikistan, and its loss indicates that government control over northern Afghanistan has completely collapsed.
In another state capital, Kunduz, hundreds of government soldiers who had previously withdrawn to the airport surrendered after the Taliban took control of the city.
“My unit, 20 soldiers, 3 humvees [military vehicles] And four pickup trucks have surrendered. “
Early in the series of rapid progress, the Taliban occupied three more state capitals. Faizabad, a city in the northwest, Fara, a city in the west, and Puruekmuri, a city in the north.
The Washington Post quoted an unnamed official as saying the capital Kabul May fall into the Taliban within 90 days, Based on US military evaluation.
Fierce fighting continues in other parts of the country, with US and Afghan planes bombing.
The psychological blow can be huge
Analysis by Inayatulhaq Yasini, editor of the BBC Kabul bureau
Mazar-i-Sharif, now the main economic center, has historically been the gateway to the country’s supply from the former Soviet Union.
The Kabul government recognizes the importance of the city, which is why the President of Afghanistan visited the city to meet with local leaders and former warlords.
If it falls, the psychological blow will be huge. The Taliban last occupied the city in the 1990s. This happened without much resistance after the deal with Abdul Rashid Dostam’s rivals.
But now he is one of the leading leaders in fighting radical groups.
More than 1,000 civilians were killed in a fierce battle between the Taliban and government forces last month, according to the United Nations. The children’s institution UNICEF warned this week: The atrocities committed against children are “higher day by day.”..
Thousands of people have fled their homes lately.
“We saw a corpse lying near the prison … there was a dog next to them,” a woman who left Kunduz told AFP.
“People have shops and businesses open, but they can still be scared in their eyes,” said one local.
The Taliban refused an international call calling for a ceasefire.
British Defense Chief of Defense General Nick Carter told the BBC that if the state collapsed, “ideal conditions” could emerge for international terrorism and violent extremism.