Donald Trump is shrugging off the refusal of some Republican leaders to endorse him, saying most of the party will back his nomination and new voters will compensate for the rest.

"Look, I'm going to get millions and millions of votes more than the Republicans would have gotten," Trump said an interview broadcast Sunday on NBC's Meet the Press.

Trump was addressing questions raised by House Speaker Paul Ryan, who is scheduled to meet with the presumptive presidential nominee on Thursday.

In an interview on ABC's This Week, Trump said he is a "very different" kind of candidate, and party unity may not be as big a factor because of new Republicans.

"I think it would be better if it were unified," Trump said, adding that "I don't think it actually has to be unified" in the more traditional sense.

"It's not called the Conservative Party," he told ABC. "This is called the Republican Party."

Ryan has said he is not yet ready to endorse Trump because of doubts about his conservatism, while other party members have flatly come out against the nominee-in-waiting. That group includes 2012 Republican nominee Mitt Romney as well as former 2016 GOP hopefuls Jeb Bush and Lindsey Graham. They cited issues ranging from Trump's abrasive language to his comments about women and Hispanics.

Trump lacks the "temperament or strength of character" to be president, Bush wrote in a Facebook post on Friday. The former Florida governor added that "he has not displayed a respect for the Constitution. And, he is not a consistent conservative."

Bush's brother and father, the two former presidents, have announced they would not attend the July convention that crowns Trump and had no plans to endorse, while Romney has denounced the New York businessman as a "phony" and a "fraud."

Graham, the South Carolina senator who like Bush lost to Trump in the Republican nomination fight, told CNN: "Good luck with Paul Ryan trying to find a conservative agenda with this guy."

In his NBC interview, Trump said Romney is "ungrateful" for his support in 2012, and that the former Massachusetts governor "choked" on his chance to beat President Obama. Trump said that Bush and Graham are angry that he beat them during the nomination fight, and he noted that both once backed a pledge to support the nominee.

"Now they're breaking," Trump said. "You know, that's a question of honor.”

The presumptive Republican nominee said he was "blindsided" by Ryan's reluctance to endorse, saying he thought he had a good relationship with the House speaker.

Ryan told CNN he wants to back the nominee, but "I'm not there right now."

Democrats are enjoying all the GOP in-fighting — particularly likely presidential nominee Hillary Clinton, who is targeting anti-Trump Republicans for the fall general election.

"Obviously I'm reaching out to Democrats, Republicans, Independents — all voters who want a candidate who is running a campaign based on issues," Clinton told CBS' Face the Nation.

Trump, saying he will beat "Crooked Hillary" easily in the fall, says most Republicans will wind up backing his candidacy.

"You know, the party's come together," Trump told NBC's Meet the Press. "I have tremendous numbers of endorsements. I'm never going to get Romney's endorsement. He choked. He blew the last election."