A German journalist who interviewed Pope Benedict XVI for a 2010 book says the pontiff told him last August that his strength was diminishing and "not much more" could be expected from him as pope.

Peter Seewald interviewed Benedict for "Light of the World," in which Benedict said that if a pope realizes he can no longer handle the papal duties "he has a right, and under some circumstances, also an obligation to resign."

In an article for German weekly Focus published Saturday, Seewald recalls asking Benedict last August what more could be expected of him and his papacy.

Seewald says Benedict replied: "From me? From me, not much more. I am an old man and my strength is running out. And I think what I have done is enough."