"These individuals will return to the country within the next one or two days," Iranian foreign ministry official Hossein Noushabadi told Iran's Tasnim state news agency.  He said most of those being flown to Iran, via Qatar, had entered the US illegally - mainly through Mexico. There has been an increased number of Iranians entering the US in recent years, including many who fear persecution at home.

White House spokesperson Abigail Jackson told the BBC: "The Trump administration is committed to fulfilling President Trump's promise to carry out the largest mass deportation operation of illegal aliens in history, using all the tools at our disposal."

Noushabadi said some of those being deported held valid US residency permits, adding that US officials had sought their consent for their return. He called on the US government "to respect the rights of Iranian migrants and their citizenship rights under international law". The New York Times, citing two senior Iranian officials familiar with the matter, said the flight of deportees was expected to arrive in Iran later on Tuesday. Iran has been working with the US on a deal to remove the Iranian nationals through its US Interests Section at the Pakistani embassy in Tehran. It is a rare instance of cooperation between Iran and the US, who do not have formal diplomatic ties. Noushabadi said as part of the deal some 400 Iranian nationals are expected to be deported from the US, with this flight considered the first phase. The US has already reached bilateral deportation agreements with a number of countries. Earlier this year, Panama and Costa Rica agreed to take in several hundred African and Asian migrants from the US. (BBC)