Former South Carolina Gov. Mark Sanford announced Sunday that he will challenge President Donald Trump for the Republican nomination in 2020.

"I am here to tell you now that I am going to get in," Sanford told Fox News host Chris Wallace on "Fox News Sunday."

Sanford, who up until this year represented South Carolina in Congress, said the Republican Party is fighting an identity crisis.

"I think we need to have a conversation about what it means to be a Republican. I think that as a Republican party we have lost our way," Sanford said.

Specifically, Sanford panned the party for its acceptance of debt, deficit growth, and unchecked spending. He said the president's "familiarity and comfort-level with debt that is ultimately leading us in the wrong direction."

Sanford also criticized Trump's trade tactics, which have been widely criticized by Republicans and Democrats, the president's leadership style, and his use of Twitter.

"We need to have a conversation about humility," Sanford said.

Sanford becomes the third Republican to mount a long-shot challenge against Trump. Former Rep. Joe Walsh (R-Ill.) and former Massachusetts Gov. Bill Weld have also committed to challenging Trump for the Republican nomination.

Sanford lost his seat in Congress after losing to a primary challenger last year. He served two terms as South Carolina governor and is perhaps best known for having an extramarital affair with an Argentine mistress.