President Donald Trump on Monday dismissed his trio of challengers for the Republican presidential nomination as “a laughingstock,” and defended the decisions by GOP leaders in a handful of states to scrap their 2020 primaries and caucuses.

“The three people are a total joke. They’re a joke. They’re a laughingstock,” Trump told reporters outside the White House before departing for a rally in North Carolina.

Former South Carolina governor and congressman Mark Sanford on Sunday became the third Republican candidate to announce plans to compete with Trump for the party’s nomination — or at least blunt the president’s momentum heading into the general election.

Sanford is joined by conservative radio show host and former Illinois congressman Joe Walsh, and former Massachusetts governor and 2016 Libertarian vice presidential nominee William Weld.

Asked whether he was willing to debate the Republicans running against him, Trump responded, “I don't know them” — going on to mock their polling numbers and tout his significant support among GOP voters.

“I guess it’s a publicity stunt,” Trump said of his rivals’ campaigns, adding: “To be honest, I'm not looking to give them any credibility. They have no credibility.”

Trump also contended he had “nothing to do with” Republican officials in Arizona, Kansas, Nevada and South Carolina moving in recent days to abandon their nominating contests next year, which he criticized as “very expensive” for state parties. POLITICO reported last week that the maneuvers will help cut off oxygen to the president’s long-shot primary challengers.

“The four states that canceled it don't want to waste their money. If there was a race, they would certainly want to do that, but they are considered to be a laughingstock,” Trump said, again blasting his opponents.