IRNA Office of the President of Germany Frank-Walter Steinmeier in a message said that expressing congratulations on the 40th anniversary of the Islamic Revolution is a common issue.
The message was released in response to some German media as criticizing Steinmeier act to issue congratulation to Iran.
According to 'Stern' media, German president in a message congratulated the anniversary of the Islamic Revolution and expressed hope for improving Iran internal affairs.
The German tabloid 'Bild' and 'Der Tagesspiegel' newpaper had earlier claimed that Steinmeier should not have extended congratulations to Iran.
Throughout Iran, millions of people took part in the annual rallies to support their 1979 Islamic Revolution in more than 1,000 other cities and towns and in 4,000 villages.
Hundreds of foreign guests, including journalists, had travelled to Iran to attend and cover the event.
The 10-day period from Imam Khomeini's return from Paris to Tehran on February 1, 1979, until the revolutions victory on February 11 is celebrated in Iran annually and is dubbed as the `Ten-Day Fajr (Dawn).'