The Trump administration has created a new unit dedicated to reviewing green card holders' criminal history to determine whether they could be deported.

President Donald Trump, who has long railed against his predecessor's efforts to vet immigrants coming into the United States, set up the Tactical Operations Division of the US Citizenship and Immigration Services to review those decisions, The New York Times reports.

There are now 40 immigration officers working under its 'LPR Operations,' dedicated to determining whether green card holders have committed fraud or pose any threats to the United States, according to internal documents obtained by the Times.

Previously, green card holders' criminal history would only be reviewed by USCIS when the immigrant applied for renewal, naturalization or another benefit.

Zach Kahler, a spokesman for USCIS, told the Daily Mail the agency is 'evolving through organizational realignments to better protect American citizens and support our mission priorities.

'USCIS's first and foremost mission is to safeguard America by vigorous vetting and screening aliens,' he said in a statement. 'We will continue to implement changes as we identify opportunities to strengthen the US immigration system.'

Kahler said those who are being re-vetted include immigrants who were arrested and convicted of various crimes, including sexual assault, domestic violence, DUI and possession of drug paraphernalia.

It also includes people who USCIS agents determined lied to get permanent resident status and some who have 'admitted to membership in an organization suspected of illegally or illicitly obtaining export-controlled information and technology for Iran's Islamic Revolutionary Guard.'

Federal law states that green card holders can be deported for various reasons, including convictions of certain crimes or fraudulently obtaining lawful permanent resident status. 

Those who are convicted of murder or drug trafficking, or some other minor offenses, could also be deported.

However other misdemeanors, such as first-time DUI that does not result in any injuries, does not typically make a green card holder eligible for deportation.

If USCIS determines that a green card holder is eligible for deportation, the immigrant usually has the chance to appear before an immigration judge who issues a decision on their case. 

But the Trump administration's effort to proactively seek green card holders for deportation has come under criticism by some former Homeland Security officials who have questioned whether it is the department's best use of resources.

USCIS had more than 11 million pending applications for a variety of immigration benefits at the end of September, a number that has roughly doubled since the end of 2019, according to the latest publicly-available data.

Internal data obtained by the Times, meanwhile, showed that of the 2,890 cases that had been reviewed as of May 7, 80 percent were deemed as requiring 'no further action.'

More than 500 green card holders remain under review, while tens of thousands more have been identified for review, a person familiar with the matter told the outlet.

'There have been a lot of questions about whether or not this is a responsible use of USCIS's resources, especially when you consider how backlogged the agency is,' said Sarah Pierce, a former policy analyst at USCIS who is now the director of special policy at the center-left think tank Third Way.

'I think the numbers only continue to raise those questions.'

The Daily Mail has reached out to the White House for comment.