Grass said he felt ashamed of his service in the Waffen SS

In a letter to the mayor of his hometown of Gdansk in Poland, Grass said his failure to disclose serving in the Waffen SS "can also be condemned".

Former Polish president Lech Walesa has dropped demands for Grass to renounce his honorary citizenship of Gdansk.

Grass stated he was drafted into the SS aged 17 "without having a say".

'Painful lesson'

The author, who was named Nobel Literature Laureate in 1999, said: "It's only now, with age, that I have found a suitable way of talking about it from a wider perspective.

"I would however like to maintain the right to affirm that I have learned the painful lesson that life gave me in my youth. My books and my political activity are testimony to that," added the 78-year-old.

Grass was contacted by authorities in Gdansk asking for an explanation of his Nazi past after his public admission earlier this month.

The city's mayor, Pawel Adamowicz, said the letter contained "answers to many questions and is very warm at the same time".

Lech Walesa initially demanded the return of Grass's Gdansk honour

Walesa said he was "no longer in conflict" with Grass after reading the letter's contents, adding: "I think he's explained himself sufficiently."

Grass was born in Gdansk in 1927, which was then known as the Free City of Danzig and had a largely German population.

He rose to prominence with the publication of The Tin Drum in 1959, which examined Germany's Nazi legacy.