EXCLUSIVEMark Morgan, a former head of Customs and Border Protection (CBP) and one of the most vocal defenders of the Trump administration’s border policies, is joining the Federation for American Immigration Reform (FAIR).

FAIR, a hawkish immigration group that advocates for border security and lower levels of immigration overall, said Morgan will serve as a senior fellow and additional spokesman for the group.

"I’m honored to serve as a senior fellow with FAIR, which is dedicated to engaging in meaningful dialogue to influence, formulate and promote responsible immigration policies for the 21st Century and beyond," Morgan said in a statement. "I am delighted to be part of the effort to seek out solutions to mitigate the tremendous burden and negative impact of uncontrolled immigration on our country’s national security and economic prosperity."

HOUSE REPUBLICANS WARN BIDEN OF ESCALATING MIGRATION CRISIS AMID SURGE IN BORDER NUMBERS 

Morgan served as both acting director of Immigration and Customs Enforcement (ICE) and as acting commissioner of CBP during the Trump administration. He had served as head of the U.S. Border Patrol under the Obama administration.

He played a prominent role as a top immigration official during an administration where cracking down on illegal immigration at the southern border was a top priority, and that saw significant pushback from Democrats and liberal activist groups. 

Morgan was vocal and passionate of his support for top administration policies -- including the construction of the wall at the southern border and policies such as the Migrant Protection Protocols (MPP). He has also been warning for months that reversing those policies, as President Biden has started to do, would lead to a disaster at the border.

BIDEN SIGNS THREE IMMIGRATION ORDERS IN LATEST MOVE TO REVERSE KEY TRUMP POLICIES

"We've been sounding this alarm during the entire Biden campaign that if he did what he promised he was going to do, we would see a crisis that would make 2019 pale in comparison," he said on "Fox News @ Night" last week.

Biden has moved quickly on immigration, ending construction of the wall, halting Trump-era travel bans, proposing a pathway to citizenship for illegal immigrants, moving to increase refugee caps and ordering a review of MPP.

FAIR, which has been supportive of many of Trump’s policies -- and frequently urged him to go further to reform U.S. immigration law, particularly on issues related to legal immigration -- has been similarly critical of Biden’s immigration policies since he took office. 

"There are very few people with as much front-line knowledge of immigration policy as Mark," FAIR President Dan Stein said in a statement. "As we reckon with an administration that appears to be bent on dismantling immigration enforcement and exercising executive power to maximize immigration even during a period of crisis and high unemployment, and efforts in Congress to grant mass amnesty to tens of millions of illegal aliens, Mark is uniquely qualified to assess the impact of those policies."

CLICK HERE TO GET THE FOX NEWS APP

The move to FAIR comes after Morgan, along with former acting Homeland Security Secretary  Chad Wolf and former deputy acting Secretary Ken Cuccinelli joined the Heritage Foundation as fellows in the Davis Institute for National Security and Foreign Policy -- although Morgan’s role at FAIR is expected to be more extensive.

He joins FAIR just as Republicans have been warning already of a rising immigration crisis. A letter to Biden from 51 Republicans on Tuesday said sources on the ground have told them that Customs and Border Protection (CBP) agents have seen the average daily flow of migrants at the border surge to more than 3,500 a day from 2,000 last month.