The United States is planning to deport some 400 Iranians, most of whom entered the country illegally, as part of US President Donald Trump’s broader crackdown on immigration, a senior Iranian official said on Tuesday.

“In the first step, they decided to deport 120 Iranians who entered the US illegally, most of whom through Mexico,” the Iranian Foreign Ministry’s director general for parliament affairs, Hossein Noushabadi, told the semi-official Tasnim news agency.

The deportation, an uncommon instance of cooperation between the two countries, came after months of talks, according to The New York Times, which first reported the move.

Noushabadi said the US was “planning to deport around 400 Iranians, most of whom entered the country illegally, in line with the new anti-immigrant approach of the US government.”

The first group of 120 would reach Iran in the next one or two days, he said.

The New York Times reported that a US-chartered flight took off from Louisiana on Monday and was scheduled to arrive in Iran via Qatar sometime on Tuesday.

Some of the Iranians had volunteered to leave after being in detention centers for months, and some had not, the newspaper said.

It was unclear what the identities of the deportees were or their reasons for trying to emigrate to the US.

According to the officials cited by the Times, those on board had either been denied asylum or had not yet appeared before a judge.

The US has historically given shelter to Iranians fleeing persecution at home, though some have been sent back in the past.

Noushabadi called on Washington to respect the rights of Iranian migrants in the United States.

“Some (returnees) had residence permits, but due to reasons stated by the US immigration office, they were included in the list. Of course, their own consent was obtained for their return,” he said.

The US and Iran have no official diplomatic ties and do not have embassies in each other’s countries. A close ally of Israel’s, the US has worked to prevent Iran from obtaining a nuclear weapon, imposing independent sanctions on the Islamic regime, and even striking its nuclear sites during Israel’s brief war on Iran in June.

The White House and the US State Department did not immediately respond to a Reuters request for comment.

Trump plans to deport a record number of people living in the US without legal status, after what he describes as high illegal border crossings under his Democratic predecessor Joe Biden.

However, his administration has struggled to increase deportation levels, even as it has created new avenues to send migrants to countries other than their own.

The US in February deported 119 people from different countries, including Iran, to Panama as part of an agreement between the two countries.