Pakistan said on Friday that it would repatriate all illegal immigrants including hundreds of thousands of Afghan nationals in orderly phases rather than in one go.

Pakistan's announcement on Tuesday of a Nov. 1 deadline for people to leave or face forcible expulsion has frayed already soured relations with Afghanistan's Taliban rulers, who said the threat to force out Afghan migrants was "unacceptable".

"It will be done in phases," the foreign office spokeswoman, Mumtaz Zahra Baloch, told reporters in Islamabad. She added the process would follow an orderly manner, in contrast to what she called some misconceptions that all of them would just be expelled in one go.

She said it could start with people with criminal records, such as someone involved in a crime or smuggling. "We will be looking into each case individually," she added.

She did not have exact data on the total number of illegal immigrants, including Afghans. Interior Minister Sarfraz Bugti said on Tuesday some 1.73 million Afghans in Pakistan had no legal documents and the number of Afghan refugees in Pakistan totalled 4.4 million.

Bugti said that the decision was taken by the country's civil and military leaders in view of rising attacks by Islamist militants, alleging that 14 out of 24 suicide bombings in Pakistan this year were carried out by Afghan nationals.

Pakistan has hosted the largest number of Afghan refugees since the Soviet invasion of Kabul in 1979.

Aid officials say Afghanistan is already facing a humanitarian crisis and the forced repatriation of large numbers of people would compound dire problems there.

Decades of war in Afghanistan largely ended in mid-2021 when the Taliban re-took control as U.S.-led foreign forces were withdrawing and a U.S.-backed government collapsed.

While Pakistan has for years favoured the Taliban as Pakistan's best option as Afghanistan's rulers, relations have deteriorated over the past couple of years, largely over accusations that Islamists fighting the Pakistani state operate from Afghan territory. The Taliban deny it.

Pakistan's foreign minister Jalil Abbas Jilani defended the order for the departure of illegal immigrants, saying no other country allowed illegal immigrants to stay and live.

"So, accordingly，this is in line with the international practice that we have taken this decision," the minister told Hong Kong's Phoenix TV on the sidelines of a forum in Tibet.

(Additional reporting by Albee Zhang and Ryan Woo in Beijing; Editing by Robert Birsel, William Maclean)