Former New York mayor and billionaire Michael Bloomberg said on Sunday he will pay $4.5 million to cover this year's US financial commitment to the Paris Climate Agreement.

President Donald Trump announced his decision to withdraw from the Paris deal in June last year, saying the accord would have cost America trillions of dollars, killed jobs, and hindered the oil, gas, coal and manufacturing industries.

But he also, at the time, said he would be open to renegotiating the deal, which was agreed by nearly 200 nations over the course of years - drawing ridicule from world and business leaders who said that would be impossible.

Bloomberg, in a CBS interview, said he hopes by next year Trump will have changed his mind.

Bloomberg will continue to provide money for the pact if the United States does not rejoin the agreement, according to a news release from Bloomberg Philanthropies, the charity he founded.