ISLAMABAD - PPP Chairman bilawal Bhutto Zardari was due to embark on an eight-day visit to the us on Sunday on the invitation of the local Pakistani diaspora. During his visit , the PPP Chairman will also visit New York and Washington, meet American legislators, senior officials and media organisations. He will also address a number of think tanks. The visit of Bilawal  comes at a time when President Zardari is in Chicago to attend an important Nato summit on the future of Afghanistan.