She asks President Donald Trump: "[P]lease do not withdraw from the Paris climate accord; this is not in the best interest of Americans," Whitman said on "Squawk on the Street." She was one of 25 CEOs who signed a letter in favor of staying, which appeared in a full-page ad in Thursday's New York Times and Wall Street Journal.
"We need to own the next generation of jobs, whether that's clean energy, or 3-D printing or immunotherapy," said Whitman, a tech billionaire who ran an unsuccessful 2010 GOP gubernatorial bid in California. She ended up supporting Democrat Hillary Clinton for president in the 2016 election.
"This is an arena America should lead and must lead," Whitman continued. "I think this will be a big mistake if he withdraws."
The White House was not immediately available to respond to CNBC's request for comment.
President Trump is expected to pull out of the Paris climate agreement, according to multiple news organizations, citing White House officials.
The president said in a tweet Wednesday evening that he would officially announce his decision on the accord from the White House Rose Garden at 3 p.m. ET Thursday.