The former head of the Vatican's doctrine office has denied any differences with Pope Francis as he said he is not upset about his earlier-than-expected dismissal.

Francis sacked German Cardinal Gerhard Mueller yesterday, declining to renew his five-year term.

Cardinal Mueller turns 70 in December, and the normal retirement age for bishops is 75.

In an interview with Mainzer Allgemeine Zeitung published today, Cardinal Mueller said Francis simply decided not to renew his mandate, wanting to limit terms as a rule "and I was the first where he put this into practice".

He said: "It doesn't make me particularly sad... Everyone has to stop at some point."

He said he would remain at the Vatican to do research, perform his role as cardinal and work in pastoral care.