Emeritus Pope Benedict arrived in Germany to be with his brother, who is in poor health, the Vatican has said.

Benedict arrived in Regensburg, Germany where his brother, the Reverend Georg Ratzinger, lives, and where "he will spend the necessary time", the Vatican said in a statement.

Benedict was accompanied by his personal secretary, Georg Gaenswein, a doctor, a nurse, an attendant and the deputy commander of the Vatican's gendarmerie corps.

Benedict is 93 and his brother is 96.

The German Bishops Conference welcomed Benedict in a statement earlier Thursday, saying ''we are happy that he has come to his homeland, where he belonged for some years to our bishops' conference, even if the occasion is sad.

"The emeritus pope will be close to his brother, whose health condition has worsened,'' the bishops' conference said.

"We wish the (emeritus) pope a good stay in Germany, and the necessary quiet to care for his brother in private."

The retired pope himself is quite frail, and while generally living a secluded retirement in a Vatican retreat house, he occasionally has appeared in public, and Pope Francis has visited him at times.

The two brothers are extremely close and share a lifelong passion for classical music.