The new law is modelled on Oregon's statute, passed in 1997, which saw 105 people die by assisted suicide in that state last year.

Governor Brown said he had carefully read material opposing the new law presented by "numbers of doctors, religious leaders and those who champion disability rights".

"I have considered the theological and religious perspectives that any deliberate shortening of one's life is sinful."

Governor Brown also said he had spoken with a Catholic bishop.

California's Catholic bishops had called on him to veto the bill.

He had also spoken to supporters of the End of Life Option Act including the family of Brittany Maynard and Archbishop Desmond Tutu.

"In the end, I was left to reflect on what I would want in the face of my own death," Governor Brown stated.

"I do not know what I would do if I were dying in prolonged and excruciating pain.

"I am certain, however, that it would be a comfort to be able to consider the options afforded by this bill.

"And I wouldn't deny that right to others."

California's End of Life Option Act passed in the state's legislature in mid-September ahead of Pope Francis's trip to the US.

The California law will permit physicians to provide lethal prescriptions to mentally competent adults who have been diagnosed with a terminal illness and face the expectation that they will die within six months.

Supporters of the new law say it has sufficient safeguards.

Oregon's law has been criticised for having unintended consequences, for degrading the quality of medical care, and for having inadequate state supervision.

California joins four other US states — Oregon, Washington, Montana and Vermont — in allowing physician-assisted suicide.

Sources

• Washington Post
• Los Angeles Times
• Los Angeles Times
• KGW.com
• Los Angeles Times
• Image: Infostormer.com