Donald Trump and his wife, Melania, right, arrive at the White House Correspondents' Association dinner in Washington on April 30. (Johnathan Ernst/Reuters)

Donald Trump said in a radio interview Wednesday that he is prepared to run for governor of New York -- provided that he doesn't face opposition in the Republican primary.

Trump said he was "ready, willing and able" to run if he is guaranteed the GOP nomination, according to the New York Daily News. Currently, Westchester County Executive Rob Astorino (R) is eyeing the race against Gov. Andrew Cuomo (D), saying he's leaning towards running. Astorino is expected to make a decision in the next month.

"I want to go in there right from the beginning, and I want to go in swinging right from the beginning," Trump said, according to NYDN. "I don’t want to be knocking Rob or knocking anybody else to win a primary."

Trump said he definitely won't run if Astorino or anybody else does: "I wouldn’t waste my time. I wouldn’t do it, and you’d make a lot of people very unhappy.”

Cuomo is hugely popular in New York and isn't considered a top GOP target, meaning whoever challenges him faces a very tall task.