A Catholic group close to Pope Francis and representatives of 25 countries on Wednesday appealed to outgoing California Governor Jerry Brown to commute all the state's 742 death sentences before laving office.

The Sant' Egidio peace group made the appeal together with the justice ministers of South Africa, Benin, Zimbabwe and Malaysia, and 21 lower-ranking officials from other countries at a conference on the death penalty held in Italy's parliament.

Mario Marazziti, a Sant' Egidio leader, asked Brown to 'declare a moratorium on all executions and begin the process of commuting the sentences into jail terms before leaving office'.

Brown, who once trained to be a priest of the Jesuit order, will leave office after completing his current two terms on January 7, when Governor-elect Gavin Newsom is sworn in.

A spokesperson for Brown had no comment.

There are currently 742 people condemned to die in California, where the last execution took place in 2006. Executions since then have been blocked by legal issues.

Sant' Egidio, which has branches in many countries and hundreds of thousands of followers around the world, is in the forefront of efforts to abolish the death penalty and help migrants. It has found great favour with the pope.

Last August, the Roman Catholic Church formally changed its teaching to declare the death penalty inadmissible, whatever the circumstance.

The 1.2 billion-member Catholic Church had for centuries allowed the death penalty in extreme cases, but the position began to change under Pope John Paul II, who died in 2005.

The Vatican has said the change to its universal catechism, a summary of Church teaching, reflected Pope Francis' total opposition to capital punishment.

The move was criticised by conservative groups in the United States, who said the Bible allowed the death penalty as a legitimate means of retributive justice.

An editorial in the Los Angeles Times last week urged Brown to commute at least the death sentences of those who committed crimes when they were young. The newspaper also urged Newsom to place a new anti-death penalty initiative on a future ballot.

Propositions to end capital punishment were defeated in 2012 2016 in California.

Capital punishment is banned in most of Europe, with Belarus the only European country that carried out executions last year, according to Amnesty International. By the end of last year, 106 countries worldwide had banned the death penalty.

In 2017, 53 countries issued death sentences and 23 of them executed at least 993 people with most executions in China, Iran, Saudi Arabia, Iraq and Pakistan.