He said: "I believe that the problem is that dictatorships feed extremism, and once the United States stops supporting dictators we can successfully tackle the extremist problem as well."
Bilawal pleaded for privacy as he pursued his studies at Oxford, where he is in his first year.
Meanwhile, Pervez Musharraf, Pakistan's president, has said his government is committed to finding the truth behind the assassination of Bhutto and vowed to punish her killers.
At the beginning of January, Musharraf asked the UK to assist in the investigation of the murder and a team of British police officers was sent to Islamabad.
Musharraf met the Scotland Yard detectives and said the Pakistan government was committed to "unearthing the evidence, finding out the truth and bringing those responsible for this heinous crime to justice".
The British police said they were thoroughly sifting the evidence to ascertain the facts.
At the same time, it was announced that the Pakistani detective who solved the 2002 murder of Daniel Pearl, the Wall Street Journal reporter, had joined the Bhutto killing inquiry.
A senior Pakistan government official said: "He has joined the investigation and will co-ordinate with the Scotland Yard team."