NEW YORK — Republican presidential candidate Donald Trump met with dozens of top fundraisers and potential donors here Thursday, kicking off an aggressive push to expand his campaign’s fundraising base in the first meeting of his national finance team.

The real estate mogul spoke to about 60 donors who are interested in funding his bid at a luncheon at the Four Seasons in midtown New York, blocks from Trump Tower. Key members of his staff and the Republican leadership, including Republican National Committee chairman Reince Priebus, attended the fundraiser.

In his remarks to the group, Trump stressed the need to rebuild the country, a central theme in his White House campaign. Reassuring supporters that he can win in November, Trump made the case that he will appeal broadly to Americans across demographic groups, saying that his strong performance in the GOP presidential primary contest proves that he has wide support.

The mood at the luncheon and strategy briefing was enthusiastic as top RNC and campaign officials laid out their plans for the general election campaign. Despite the campaign’s late start in setting up a fundraising infrastructure, there was a widespread sense of optimism that the group would be able to begin pulling in significant sums, according to participants.

The candidate wasn't asked about the controversy over his attacks on the impartiality of U.S. District Judge Gonzalo Curiel, who is overseeing a pair of cases related to the Trump University for-profit education business. But the real estate developer told the group that he will convince Americans he has no biases, according to people in the room.

Trump has attacked Curiel in highly personal terms, igniting a firestorm of criticism after he suggested that Curiel’s ethnicity posed a conflict of interest in the two cases he is overseeing against Trump University. Curiel, who is of Hispanic descent, was born in Indiana.

New Jersey Gov. Chris Christie — a key Trump ally and a major liaison to establishment Republicans — defended Trump during the meeting, according to several attendees. John Catsimatidis, a wealthy businessman who ran unsuccessfully for mayor of New York in 2013, said that Christie moved to assuage concerns over the recent weeks of controversy, saying that “people make mistakes, [then] they take it back.”

“I think Donald is learning how to be a candidate the way I learned how to be a candidate,” said Catsimatidis, who has also donated to Hillary Clinton’s campaign.

Trump’s chief strategist, Paul Manafort, said after the meeting during a brief gaggle with reporters that the campaign is confident it will be able to raise enough funds to win in November. He did not give a firm fundraising goal.

Already, around 30 state chairs have signed on to raise funds. Trump is set to headline a busy stretch of fundraisers for the rest of the month, from Virginia to Arizona.

Still, his team has a small window to crank up its finance operation in order to bring in the hundreds of millions needed to fund his campaign and the party. By the end of June 2012, presidential nominee Mitt Romney had already raised $140 million in conjunction with the RNC.