Newsom explained that he spoke to the president "because I wanted to extend to him my appreciation" for his visit to California areas hit by wildfires and to "express the fact that the people in those communities were grateful to him".
"Our death penalty system has been - by any measure - a failure", Newsom will say.
"The intentional killing of another person is wrong and as governor, I will not oversee the execution of any individual", he said in prepared remarks.
California voters have repeatedly rejected abolishing capital punishment but there is a court imposed moratorium on the death penalty.
Kent Scheidegger, legal director of the Criminal Justice Legal Foundation, which has been fighting in court to force the state to resume executions, said blocking Newsom's move may be hard. And it said five condemned California inmates were eventually exonerated since 1973.
California has not put an inmate to death since 2006, amid legal challenges to its execution protocols and discomfort with the sentence among political leaders.
According to the state's Department of Corrections and Rehabilitation death row list (pdf), 737 inmates were slated to be executed prior to the executive order.
Ellen Kreitzberg, a death penalty expert and opponent at Santa Clara University law school in California, welcomed Newsom's move.
Brie Larson's 'Captain Marvel' training included how to make a cool face
Akira Akbar is instantly endearing as Maria's whip-smart daughter Monica. That ends up being one of the movie's most fun moments.
Kim Kardashian is speaking out to voice her support for ending the death penalty. Because the state hasn't executed anyone since 2006 due to legal challenges, Newsom's order is largely viewed as symbolic.
"Defying voters, the Governor of California will halt all death penalty executions of 737 stone cold killers", Trump said. A new execution protocol is under review, but Newsom's order will withdraw it.
Newsom, who became governor in January of this year, said the death penalty "has discriminated against defendants who are mentally ill, black and brown, or can't afford expensive legal representation".
"You can't make this up Anderson", Newsom said with a laugh.
Just last month, Newsom issued an executive order that allowed for new DNA testing of evidence in the high-profile case of death row inmate Kevin Cooper, who was sentenced in 1985 for the murders of four people and has exhausted his appeals.
Most industrialized nations have abolished the death penalty, yet the USA executes more people than any other democracy on the planet.
Eighteen other states and the District of Columbia have abolished the death penalty.
But Newsom's action will anger death penalty proponents. "The disparities are really real and raw to me now, as I spend every week working on the issues of paroles and commutations and, substantively I see those disparities".
- Facebook, Instagram and WhatsApp suffered a global outage. What happened?
- Windows 10 now automatically uninstalls b0rked updates
- Brendan Rodgers frustrated to lose first game as Leicester City boss
- Giants trade Odell BeckhamJr. to Cleveland Browns in National Football League blockbuster
- Second person cured of HIV in major medical breakthrough
- Patriots are trading for Eagles defensive end Michael Bennett
- Weather warning for the Yorkshire coast - here's why and when
- Arsenal 2-0 Manchester United: Three Things We Learned
- Dems postpone anti-Semitism resolution after complaints from … anti-Semites
- Trump's 2020 budget request to seek $8.6 billion for border wall