President-elect Donald Trump has tapped Sen. Jeff Sessions as his attorney general pick, multiple sources familiar with the decision confirmed to NBC News.

In February, the Alabama senator became the first sitting senator to endorseTrump during his campaign. His name was also floated as a possible running mate for Trump.

Sessions is chairman of the Senate Subcommittee on Immigration, and served as an adviser on Trump’s immigration policy plan during his campaign.

When he first endorsed Trump, Sessions praised the then-GOP contender as someone who would finally fix illegal immigration.