US senator John Kerry says his country is deeply sorry over killing of two Pakistanis by US official

US senator John Kerry said Tuesday his country was "deeply sorry" over the killing of two Pakistanis by a US official, after arriving in Pakistan to resolve a diplomatic row over the man.
  
"We are deeply, deeply sorry for that tragic incident," Kerry told a press conference soon after arriving in Pakistan's eastern city of Lahore.
  
"I want to come here to express our deepest regret for those tragic events and to express the sorrow of American people for the loss of life that has taken place," he said.