Iranian President Mahmoud Ahmadinejad said nothing about nuclear issues in a letter he sent to German Chancellor Angela Merkel this week but lashed out at Israel, a government spokesman said.
"The letter contained no pronouncements about the Iranian nuclear programme," Ulrich Wilhelm told reporters.
"Instead it contained a lot of wide-ranging remarks, including about Israel, its right to exist and the Holocaust which we find completely unacceptable.
"It is in no way acceptable to question these facts, as Chancellor Merkel has made clear."
Wilhelm said the hardline Iranian president remained silent about the current crisis in the Middle East, which Iran is accused of fueling by backing Hezbollah.
Ahmadinejad expressed a wish for closer cooperation between Tehran and Berlin, he said.
Asked if Merkel had responded to the letter, Wilhelm said she had "no intention of engaging in a lengthy correspondence" with Ahmadinejad.
The spokesman said Berlin would not make public the full content of the missive, which was written in Farsi and handed to the German embassy in Tehran by Foreign Minister Manouchehr Mottaki on Wednesday.
Ahmadinejad, who has repeatedly called for Israel to be wiped off the map and questioned the Holocaust, in May wrote to US President George W. Bush.
That letter ended a 26-year break in top level contacts with Washington but also offered no concessions in the nuclear dispute raging between Tehran and world powers.
Iran on Thursday said it wanted to continue uranium enrichment work and would wait until late August to respond to an international package of incentives in exchange for freezing that work, which Europe and the United States fear could be hiding atom bomb development.
