He said he would prefer to find a church in Rome where he could continue hearing confessions.

Speaking to the Spanish-language broadcaster TelevisaUnivision, Francis, 85, denied he was planning to retire any time soon but said "the door is open".

Pope Benedict XVI stepped down in 2013, becoming the first pope to do so in 600 years.

He has lived in a monastery in the Vatican City since then.

Francis said the Vatican needs to better regulate Benedict's role of emeritus pope - but having him on hand has gone well.

Some cardinals and canon lawyers have questioned Benedict's decisions on retirement, including his decision to continue wearing the white cassock of the papacy.

Another point of contention has been Benedict, 95, refusing to revert back to his birth name, Joseph Ratzinger.

Critics say those choices and Benedict's continued presence in the Vatican have been confusing for Catholics and threaten the unity of the Church.

Traditionalists have been able to use Benedict as a conservative point of reference when they've been unhappy with Francis's decisions, they say.

Francis described Benedict as a "saintly and discreet man", adding: "But in the future, things should be delineated more, or things should be made more explicit."

The pope added: "I think for having taken the first step after so many centuries, he gets 10 points. It's a marvel."

Francis said he would also step down if the time was right and would consider taking up residence in the Basilica of St John Lateran, which is the traditional seat of the bishop of Rome.

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He said he had an apartment in Buenos Aires where he could continue hearing confessions at a nearby church and visiting the sick at a hospital.

"This is what I thought for Buenos Aires," he said. "I think this scenario, if I survive until a resignation - it's possible I might die before ... I'd like something like this."

Pope questioned on abortion

In a wide-ranging interview, he was asked whether Catholic politicians who support abortion rights should continue receiving the sacraments.

He said abortion was a matter of conscience for elected officials to work out for themselves.

Joe Biden and Nancy Pelosi have sparked a heated debate over whether it was appropriate for them to criticise the US Supreme Court decision to overturn the right to access abortion, given that they are both Catholic.

The Catholic Church opposes abortion but US bishops decided not to formally rebuke Mr Biden for supporting abortion rights.

"I leave it to his conscience and that he speaks to his bishop, his pastor, his parish priest, about that inconsistency," the pope said.

Ms Pelosi's bishop, San Francisco Archbishop Salvatore Cordileone, has banned her from receiving Communion in his archdiocese, though she recently received Communion during a papal mass at St Peter's Basilica in Vatican City.