Sharif was due to visit Washington to participate in the fourth Nuclear Security Summit on March 31 hosted by US President Barack Obama.
"Prime Minister Nawaz Sharif has cancelled his upcoming visit to the United States," Radio Pakistan tweeted minutes before Sharif's address to the nation.
At least 72 people, including 29 children, were killed and 233 were injured in a blast near Gulshan-e-IqbalPark in Lahore on Easter Sunday.
A faction of the Tehreek-e-Taliban Pakistan, Jamaatul Ahrar, claimed responsibility for the deadly suicide attack, saying Christians were their target.
Special Assistant to the prime minister on Foreign Affairs will now represent the premier at the crucial global event, Express News reported.
According to media reports, Sharif and Prime Minister Narendra Modi were likely to meet on the sidelines of the Summit.
Earlier in the day, Sharif cancelled his trip to UK, citing the the terror attack in Lahore.
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