President-elect Donald Trump will officially nominate former Georgia Gov. Sonny Perdue to be secretary of agriculture Thursday, a senior transition source told Fox News.

The nomination was expected to be announced by Vice President-elect Mike Pence during a press briefing with incoming White House Press secretary Sean Spicer Thursday morning.

Perdue, who in 2002 became the first Republican to be elected Georgia governor in 130 years, had long been considered the favorite to head the Agriculture Department in a Trump administration, with one source describing him to Fox News earlier this month as a "lock" for the position.

Perdue, 70, would be the first Southerner to lead the Agriculture Department in more than two decades. He comes from the small city of Bonaire in rural central Georgia, where he built businesses in grain trading and trucking. He is the cousin of Sen. David Perdue, R-Ga.

During Perdue's tenure as governor, Georgia adopted tough new food-safety regulations after a deadly U.S. salmonella outbreak was traced to Georgia-made peanut butter. He moved the state office that issues water permits for irrigation and other agricultural uses from Atlanta to rural south Georgia, where it would be closer to farmers. And Perdue poured millions of state dollars into Go Fish, a program that aimed to lure bass fishing tournaments to the state.

Perdue's nomination rounds out Trump's Cabinet choices. Sources told Fox News that the transition team wanted to complete the nominations by Friday.

Senate Republicans are pressing Democrats to allow confirmation votes for several of Trump's nominees on Friday evening, hours after he is inaugurated as the 45th president. Among those expected to be considered by the full Senate Friday are Defense Secretary nominee James Mattis, Homeland Security Secretary nominee John Kelly and Rep. Mike Pompeo, R-Kan., for CIA Director.

Fox News' Ed Henry, John Roberts and Chad Pergram contributed to this report. The Associated Press also contributed to this report.