The investor was asked about his views on the trade conflict and use of tariffs.
"I think it is very dangerous, and I think he’s [Trump] on the wrong track, and I hope he backs off," Cooperman said Tuesday on CNBC's "Halftime Report." "I think the market is complacent ... I think the market is assuming by the way it is acting as he has done often in the past, he backs off."
The hedge-fund manager noted there were previous incidents where Trump escalated conflict and then de-escalated later to "claim victory."
Last week Trump said the stock market rally since his election victory gives him the opportunity to be more aggressive in his trade war with China and other countries.
“This is the time. You know the expression 'We’re playing with the bank’s money,'” he told CNBC's Joe Kernen in a “Squawk Box” interview aired Friday.
So far in the trade war between the two largest economic powers in the world, the U.S. has slapped tariffs on just $34 billion of Chinese products, which China met with retaliatory duties.
On Monday Cooperman revealed he is returning outside investor capital at year-end and converting Omega into a family office.
"I turned 75 last April. It is my understanding that if you make it past 65 and cancer doesn’t get you, you can expect to live on average to 85. Hopefully, I can improve on that average, but in any event I don’t want to spend the rest of my life chasing the S&P 500 and focused on generating returns on investor capital," Cooperman said in the note to clients Monday.
Cooperman's main fund generated annualized returns of 12.4 percent since inception versus the S&P 500's 9.5 percent return including reinvested dividends, according to Institutional Investor.
Omega agreed last year to a $4.9 million settlement with the Securities and Exchange Commission after allegations of insider trading. Omega Advisors admitted to no wrongdoing. Investors redeemed $4 billion in capital during the SEC investigation, according to Institutional Investor.
Cooperman, chairman and CEO of Omega Advisors, founded the firm in 1991. It had approximately $3.6 billion in assets under management as of June 30. The investor has a net worth of $3.2 billion, according to Forbes.