Trump originally tweeted about the event Tuesday, and an adviser close to the real estate mogul confirmed to The Associated Press the $50,000-per-head fundraiser, expected to raise at least $2.5 million for the Romney campaign.

But when the AP asked Romney traveling press secretary Rick Gorka if the former Massachusetts governor would be in attendance, the spokesman said there would be "no meeting" with Trump this week.

“That won't be happening this week,” Gorka told the AP.

Asked again about the fundraiser Friday, the Romney campaign declined to comment. Reporters traveling with the candidate accompanied him to New York City from Washington Thursday afternoon, but were not told whether he would be attending the fundraiser.

Trump spokesman Michael Cohen said Friday that both Romney and Trump were in attendance, but emphasized that Trump did not help organize the event.

"The event, attended by Governor Romney and Donald TrumpDonald John TrumpFlynn to campaign for Montana GOP Senate candidate Trump considering pardon for boxing legend after call from Sylvester Stallone Decline in EPA enforcement won't keep climate bill from coming MORE was a major success raising millions of dollars for the campaign. Governor Romney was extremely energized and elated to spend time with the attendees; including several of his important surrogates like Mr. Trump," Cohen said in an email. 

Romney's relationship with the reality television show host has become a hot button issue for the campaign, with the president's reelection team criticizing the Republican challenger for associating with Trump, who has questioned whether President Obama was born in the United States.

"I don’t have the requisite degrees to climb into Donald Trump’s head or even his hair so I don’t know what motivates him. The question is why Gov. Romney wouldn’t repudiate those tactics," Obama senior strategist David Axelrod said to Current TV in May. Axelrod went on to say Trump had made a "fool" of himself in suggesting a conspiracy about the president's birthplace.

Romney has defended fundraising with the real estate mogul, saying while he disagreed on the "birther" issue, he was seeking a broad-tent candidacy.

"You know, I don't agree with all the people who support me, and my guess is they don't all agree with everything I believe in. But I need to get 50.1 percent or more, and I'm appreciative to have the help of a lot of good people," Romney told reporters in May.