The United Nations says the Taliban, Afghanistan’s rulers since last month, has challenged the credentials of Afghanistan’s former UN ambassador and are asking to speak at the UN General Assembly’s high-level meeting of world leaders.

The question facing UN officials comes about a month after the Taliban swept to power as the US prepared to withdraw from Afghanistan at the end of August.

The Taliban stunned the world by taking territory with surprising speed and little resistance from the US-trained Afghan military. The western-backed government collapsed.

UN spokesman Stephane Dujarric said Secretary-General Antonio Guterres received a communication on September 15 from the currently accredited Afghan Ambassador, Ghulam Isaczai, with the list of Afghanistan’s delegation for the assembly’s 76th annual session.

Five days later, Mr Guterres received another communication with the letterhead “Islamic Emirate of Afghanistan, Ministry of Foreign Affairs,” signed by “Ameer Khan Muttaqi” as “Minister of Foreign Affairs,” requesting to participate in the UN gathering of world leaders.

Mr Muttaqi said in the letter that former Afghan president Ashraf Ghani was “ousted” as of August 15 and that countries across the world “no longer recognise him as president,” and therefore Mr Isaczai no longer represented Afghanistan, Mr Dujarric said.

The Taliban said it was nominating a new UN permanent representative, Mohammad Suhail Shaheen, the UN spokesman said.

In cases of disputes about seats at the UN, the General Assembly’s nine-member Credentials Committee must meet to make a decision. Both letters have been sent to the committee, Mr Dujarric said.

“No meeting of the credentials committee has been scheduled so far,” UN deputy spokesman Farhan Haq said.

Afghanistan is scheduled to give the last speech on the final day of the high-level meeting on September 27.

-AAP