Delawar said that the US withdrawal was a result of the Taliban bringing Afghanistan's population over to its side under the "principle of Islam".
"The United States was forced to leave our territory," he said.
He added that there was no agreement with the United States for the Taliban not to attack administrative centres remaining under Kabul's control. "These are our internal affairs," Delawar said.
This week more than 1,000 Afghan troops fled into Tajikistan after a blistering offensive by the Taliban in the north of Afghanistan.
Afghan authorities have vowed to retake all the districts lost to the insurgents and deployed hundreds of commandos to counter their offensive in the north.
Moscow is closely watching the offensive, concerned about the security of Central Asian countries where it maintains military bases.
Russian foreign ministry spokeswoman Maria Zakharova said Friday that the Taliban "currently controls about two-thirds" of Afghanistan's border with ex-Soviet Tajikistan.
On Thursday, a Taliban delegation in Moscow met with the Kremlin's envoy for Afghanistan, Zamir Kabulov, while the Russian foreign ministry released a statement saying that it had received assurances Central Asian borders would not be violated.
US president Joe Biden on Thursday defended his country's withdrawal from Afghanistan, though he admitted that it was "highly unlikely" Kabul would be able to control the entire country.