The Pakistani government said Thursday it would open several "holding centres" for undocumented migrants as a deportation deadline looms for hundreds of thousands of Afghans.

Islamabad has given Afghans it says are living illegally in Pakistan until November 1 to leave voluntarily or face deportation -- an order the Taliban government says amounts to harassment.

"These centres have been named as 'holding centres'. Illegal immigrants will be kept there," Sarfraz Bugti, the caretaker interior minister, said at a press conference.

"They will be provided with medical facilities and food. Children, women and elders will be treated with special respect. But at the same time, after November 1st, we will not compromise on illegal immigrants," Bugti said, without giving further details.

Feroz Jamal, a spokesman for the Khyber Pakhtunkhwa government, said three centres would be ready in the province, which borders Afghanistan, by the deadline.

The order comes as Pakistan grapples with a rise in attacks the government blames on militants operating from Afghanistan, a charge Kabul routinely denies.

There is also rising anti-Afghan sentiment as a prolonged economic hardship burdens the Pakistani state.

Afghans have poured into Pakistan by the millions over decades of conflict during the Soviet invasion, the following civil war and the US-led occupation.

Around 1.3 million are registered refugees and 880,000 more have legal status to remain in Pakistan, according to United Nations figures.

The Pakistani government says a further 1.7 million Afghans are in Pakistan illegally.

Hundreds of thousands of Afghans are estimated to have crossed since the Taliban seized power in Kabul in August 2021 and imposed their austere version of Islamic law, with many migrants seeking asylum in third countries.

Police and politicians have said a recent round-up targeted only those without legal status and was in response to rising crime and poor immigration regulation that has strained resources.

But Afghans have accused authorities of indiscriminate arrests, ignoring valid documents and extorting people for money.

The interior minister also warned that Pakistanis sheltering undocumented Afghans would be "dealt with sternly" and Afghans with fake documents would be "punished".

Afghanistan is struggling through its own economic hardship, cut off from the international banking system and heavily reliant on humanitarian aid, particularly as the bitter cold winter months set in.