President Donald Trump told The New York Times in an interview published Wednesday that there is a certain “red-line” he believes special counsel Robert Mueller shouldn’t cross while carrying out the Russia investigation: digging into his finances.

Asked by Times reporters Michael Schmidt and Maggie Haberman about whether an investigation into Trump’s finances would be a breach of a “red line,” Trump said “I would say yeah.”

“By the way, I would say, I don’t – I don’t – I mean, it’s possible there’s a condo or something, so, you know, I sell a lot of condo units, and somebody from Russia buys a condo, who knows?” Trump said. “I don’t make money from Russia. In fact, I put out a letter saying that I don’t make – from one of the most highly respected law firms, accounting firms. I don’t have buildings in Russia. They said I own buildings in Russia. I don’t.

“They said I made money from Russia. I don’t,” Trump continued. “It’s not my thing. I don’t, I don’t do that. Over the years, I’ve looked at maybe doing a deal in Russia, but I never did one. Other than I held the Miss Universe pageant there eight, nine years.”

Trump said digging into his finances would be a "violation" of what the investigation is supposed to focus on. On Thursday, Bloomberg reported Mueller is expanding the Russia probe to include Trump's business dealings.

"Look, this is about Russia," he said. "So I think if he wants to go, my finances are extremely good, my company is an unbelievably successful company. And actually, when I do my filings, people say, 'Man.' People have no idea how successful this is. It's a great company. But I don't even think about the company anymore. I think about this."

"Cause one thing, when you do this, companies seem very trivial. OK?" he continued. "I really mean that. They seem very trivial. But I have no income from Russia. I don't do business with Russia. The gentleman that you mentioned, with his son, two nice people [Russian billionaire Aras Agalarov and his pop-star son Emin]. But basically, they brought the Miss Universe pageant to Russia to open up, you know, one of their jobs. Perhaps the convention center where it was held. It was a nice evening, and I left. I left, you know, I left Moscow. It wasn't Moscow, it was outside of Moscow."

Though Trump did acknowledge that he believes Mueller poking through his finances would cross a "red line," he would not confirm to the Times whether such investigating would lead him to firing the special counsel.

"I can't answer that question because I don't think it's going to happen," he said.

Earlier in the interview, Trump mentioned how Mueller had interviewed for the vacant FBI director post after the president ousted FBI Director James Comey in May. Trump expressed shock that Deputy Attorney General Rod Rosenstein named Mueller as special counsel "the next day" following the job interview.

"I said, what the hell is this all about?" Trump said. "Talk about conflicts? But he was interviewing for the job. There were many other conflicts that I haven't said, but I will at some point."

Mueller is tasked with overseeing the investigation into Russian interference in the 2016 presidential election, and that includes whether Trump's campaign colluded with Russian officials. Mueller's team is already investigating the finances of White House senior adviser Jared Kushner, with federal prosecutors also taking a look at the financial dealings of Trump associates such as former campaign chairman Paul Manafort and former National Security Adviser Michael Flynn.