Taliban insurgents tightened their grip on captured Afghan territory on Tuesday, now controlling 65% of the country, as U.S. President Joe Biden urged the nation’s leaders to fight for their homeland, Reuters reported.

Pul-e-Khumri, capital of the northern province of Baghlan, fell to the Taliban on Tuesday evening, according to residents who reported Afghan security forces retreating toward the Kelagi desert, home to a large Afghan army base, Reuters said.

Pul-e-Khumri became the seventh regional capital to come under the control of the Islamist militants in about a week.

“Afghan leaders have to come together,” Biden told reporters at the White House, saying the Afghan troops outnumber the Taliban and must want to fight. “They’ve got to fight for themselves, fight for their nation.”

According to the Reuters the U.S. president said he does not regret his decision to withdraw, noting that Washington has spent more than $1 trillion over 20 years and lost thousands of troops. He said the United States continues to provide significant air support, food, equipment and salaries to Afghan forces.

In Kabul, Afghan President Ashraf Ghani said he was seeking help from regional militias he has squabbled with for years. He appealed to civilians to defend Afghanistan’s “democratic fabric.”

In Aibak, a provincial capital between the northern city of Mazar-i-Sharif and Kabul, Taliban fighters were moving into government buildings. Most government forces appeared to have withdrawn, Reuters reported.

“The only way is self-imposed house arrest or to find a way to leave for Kabul,” said tax officer Sher Mohamed Abbas, when asked about living conditions in Aibak.

“But then even Kabul is not a safe option anymore,” said Abbas, who supports a family of nine.

The north for years was Afghanistan’s most peaceful region, with only a minimal Taliban presence. The militants’ strategy appears to be to take the north, and border crossings in the north, west and south, and then close in on Kabul.

The Taliban, battling to defeat the U.S-backed government and reimpose strict Islamic law with peace talks at an impasse, met little resistance as they swept into Aibak on Monday.

A spokesman for the group’s political office told Al Jazeera TV on Tuesday that the group is committed to the negotiation path in Doha and does not want it to collapse.

Taliban forces now control 65% of Afghanistan, threaten to take 11 provincial capitals and seek to deprive Kabul of its traditional support from national forces in the north, a senior European Union official said on Tuesday.

The government has withdrawn from hard-to-defend rural districts to focus on holding population centers. Officials have appealed for pressure on Pakistan to stop Taliban reinforcements and supplies flowing over the border. Pakistan denies backing the Taliban.

The United States has been carrying out some air strikes to support government troops. Defense Department spokesman John Kirby said the strikes were having a “kinetic” effect on the Taliban, but acknowledged limitations.

“Nobody has suggested here that air strikes are a panacea, that will solve all the problems of the conditions on the ground. We’ve never said that,” Kirby said.