Nineteen-year-old Bilawal Bhutto Zardari, a history student at Oxford University, took over as the chairman of his mother's Pakistan People's Party on Sunday, days after she was assassinated.

He said in a message to people who left condolences on the social networking site that he was still just a student who enjoyed eating junk food and watching television, but added that he would try to learn.

"I am not a born leader. I am not a politician or a great thinker," he wrote in the message posted on Monday, which is his first public statement since a few brief words when he was appointed party leader.

"I'm merely a student. I do the things that students do like make mistakes, eat junk food, watch Buffy (a reference to a US television series) but most importantly of all learn," he said.

My time to lead will come but for now I'm the one asking questions, not the one answering them."

Bhutto's party could not be immediately reached to confirm the message was authentic. The teen's father has already confirmed his son has an account on Facebook.

The heir to the Bhutto dynasty flew out of Pakistan on Tuesday with his sisters, stopping over in Dubai, where he spent many of his teenage years in exile from Pakistan, before returning to university.

His father, Asif Ali Zardari, is taking the reins of Bhutto's party until he is old and experienced enough to be a full-time leader, and he said that in that time he had much to get to grips with.

"People have questioned why I want to partake in a future that will put my life, and the lives of those around me, in constant and critical danger," he wrote on Facebook.

"People have questioned why a person of only nineteen years of age feels he has the ability to be able to achieve greatness for a nation in turmoil. I can say this much in response: these are the right questions to be asking. These questions are what the foundations of democracy and a free society are built on. The important thing is not to stop questioning."

Bhutto Zardari went on to thank people for their messages of support, describing them as his ‘’brothers and sisters’, and paying tribute to the other people who died in the gun and suicide bomb attack on Thursday.

"I'm sorry I don't have the time to respond to every single one but I have read them all and am overcome with emotion when reading about the grief you all feel," he wrote.

"This is a time of global mourning, and I feel honoured that my mother's memory and message is cherished so dearly by such an incomprehensible number of people."