Donald Trump, left, and Sen. Marco Rubio (R-Florida) at a debate. REUTERS/Jonathan Ernst Republican presidential frontrunner Donald Trump said Saturday that rival Marco Rubio should drop out of the race.

"I think it's time for Marco to clean the deck. I really do. And I say that respectfully," Trump said at a press conference in Florida.

Trump held the press conference after four states held primaries or caucuses earlier in the day. Trump was projected to win Kentucky and Louisiana, while Cruz won Kansas and Maine.

"I think Marco Rubio had a very, very bad night," Trump said. "And personally I'd call on him to drop out of the race. I think it's time now that he drop out of the race. I really think so. I think it's probably time."

Trump's call echoes that of another presidential candidate, Ted Cruz, who has urged the non-Trump candidates to drop out so that a coalition can form against the Republican frontrunner. Rubio, a Florida senator, has only won one state — Minnesota — while Cruz has also notched victories in Texas, Oklahoma, Iowa, and Alaska.

"You got to be able to win. He has not been able to win. And I think that it's time that he drops out," Trump said.

Both Rubio and Ohio Gov. John Kasich have suggested that they intend to turn their campaigns around by winning their home states, which vote later this month. But Trump said he was more than ready for a head-to-head race against Cruz in the primary.

"I would love to take on Ted one-on-one," Trump said. "That would be so much fun. Because Ted can't win New York. He can't win New Jersey. He can't win Pennsylvania. He can't win California. I want Ted one-on-one, OK?"