Russia has urged Western leaders to unfreeze Afghanistan's assets to fund humanitarian relief and avert an exodus of migrants to Europe fuelled by the Taliban's takeover in August.

The international community does not recognise the hardline Islamist group, which gained control of Afghanistan in August after foreign troops hastily withdrew from a two-decade deployment.

More than half of Afghanistan's 38 million people are facing food shortages, according to the United Nations, with the winter forcing millions to choose between migration and starvation.

Zamir Kabulov, the Kremlin's envoy to Afghanistan, said that Russia had warned the West its hold on assets and transfers could see thousands of Afghan families "run to Europe this winter".

"The West is afraid of migration flows," he told the Russian news agency RIA Novosti.

"So let's unfreeze Afghan money. We must do everything we can so there isn't any need for hundreds of thousands of Afghan families to leave the country."

Washington seized nearly $9.5 billion in assets belonging to the Afghan central bank after the Taliban gained control of the country and the aid-dependent economy has effectively collapsed.

Russia since has voiced concerns over the proliferation of terror groups in the country, including the Islamic State group, and warned terror groups planned to infiltrate neighbouring ex-Soviet countries posing as refugees.

Meanwhile, Afghanistan's finance ministry under the Taliban government has prepared a draft national budget that, for the first time in two decades, is funded without foreign aid, a spokesman said.

Finance ministry spokesman Ahmad Wali Haqmal did not disclose the size of the draft budget -- which runs until December 2022 -- but told AFP it would go to the cabinet for approval before being published.

"We are trying to finance it from our domestic revenues -- and we believe we can," he told state television in an interview shared on Twitter.

The Taliban also made a fresh appeal yesterday for Afghanistan's seat at the United Nations after the ambassador of the former US-backed government left his post.

The UN seat, and some other embassies abroad, are at the centre of a tug-of-war between exiled diplomats of the old government and Afghanistan's new Islamist rulers. No country has yet recognised the Taliban regime.

Assistant UN spokesman Farhan Haq told AFP that Afghan ambassador Ghulam Isaczai "relinquished his position as of December 15", according to a letter they received Thursday.

The Taliban's nominee for the position, Suhail Shaheen, said the seat should be now given to the new government of Afghanistan, adding it was a matter of credibility for the world body.