California governor Gavin Newsom said capital punishment is 'incompatible' with his state's values. (EPA Images pic)LOS ANGELES: California governor Gavin Newsom said Thursday he was commuting all death sentences across the state to life imprisonment, in a move that will affect over 500 prisoners.

Newsom, who is widely expected to make a run for the White House in 2028, said capital punishment was "incompatible" with the values of the most populous state in the US.

"Today I am acting on my long and deeply held conviction that individually and collectively we are stronger as a society when we reject state-sanctioned killing," he wrote in a letter addressed "to all Californians".

With 548 people awaiting execution in California, the state has one of the largest death row populations in the world.