Mr Cameron said Ramadan was a time to remind us of our duties and responsibilities and the importance of charity.
To all Muslim communities in the United Kingdom and around the world, I send you my warmest wishes at this time of Ramadan.
This is a time for Muslims all over the world to put aside thoughts of themselves, and think of others. The terrible scenes of famine and suffering in the Horn of Africa cry out to all of us. They remind us of our duties and responsibilities to those beyond our shores.
The importance of charity at this time is clear and I am proud that many different communities in the United Kingdom continue to come together to support many thousands - indeed millions - in desperate need.
As the holy month of Ramadan begins I wish you all peace and happiness.