Some media outlets in Pakistan are reporting that Sheikh Rashid Ahmed failed to get clearance from the U.S. Department of Homeland Security when he tried to board a Pakistan International Airlines flight on Friday.
Ahmed is a member of Pakistan's national assembly.
He is quoted by the Pakistani news website the Daily Times as saying he received a visa from the Canadian government to visit Canada.
The Daily Times reported Ahmed was attending a Pakistan Day celebration in Canada today.
Another website, the Nation, reported he was travelling to Calgary to attend a meeting of his party members.