Pope Francis asks for prayers for 'very ill' predecessor Pope Benedict

Pope Francis has appealed for prayers for his predecessor Pope Benedict XVI who, he said, is "very ill".

The 95-year-old, who now lives quietly in Vatican City, became the first pope to resign in 600 years when he stepped down in 2013. At the end of his general audience on Wednesday, Francis said he was praying for Benedict. "I would like to ask all of you to pray a special prayer for Pope Emeritus Benedict," Francis said .

He called on people to "remember him, because he is very ill, asking the Lord to console and support him".

Benedict, who in 2013 became the first pontiff to resign in six centuries, has almost entirely withdrawn from public view.

The few photographs that have emerged of him have shown him to be in increasingly frail health.

Back in 2013, he had cited his declining physical and mental health in his decision to become the first pope since 1415 to give up the job as head of the worldwide Catholic church.

In April, Benedict's long-time secretary, Archbishop Georg Gaenswein, told Vatican News the ex-pope was "physically relatively weak and fragile", but "in good spirits".

Pope Francis (right) and Pope Emeritus Benedict XVI meeting with new cardinals last August.