Washington (CNN) Former South Carolina Gov. Mark Sanford will launch a longshot primary challenge for the 2020 Republican nomination, he announced Sunday, giving President Donald Trump another Republican challenger as he runs for reelection.

"I had planned to announce that back home this week. We had a hurricane come visit us on the coast of South Carolina so that sort of disrupted plans on that front," Sanford said in an interview on "Fox News Sunday." "But I am here to tell you now, that I am going to get in."

When asked why he was running, he said because "I think we need to have a conversation on what it means to be a Republican," adding that he thinks the Republican Party has lost its way on "a couple different fronts."

He becomes the third Republican to mount a primary challenge against the President. In April, former Massachusetts Gov. Bill Weld officially entered the race, and last month, former Illinois Rep. Joe Walsh announced his candidacy . Trump's campaign had a one-word response to Sanford's announcement: "irrelevant," campaign spokesman Tim Murtaugh said.

Sanford, discussing what was then a potential candidacy, told CNN's Brianna Keilar in July there has been "no discussion of debt, deficit and government spending in Washington these days," and that those issues would be a focal point of his campaign were he to run. However, although Sanford has been a frequent critic of Trump, he has said he would back the President instead of a Democrat.

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