Chuck Hagel, the first US defense secretary to visit Pakistan in four years, met Monday with Prime Minister Nawaz Sharif and visited the newly appointed Pakistan chief of staff, Gen. Raheel Sharif, at Army headquarters in Rawalpindi. American officials reported that Hagel requested the reopening of the key Torkham gate checkpoint through the Khyber Pass to enable the evacuation of US military equipment from Afghanistan. The traffic was halted last week for fear that protesters led by the former cricket star Imran Khan’s Tehreek-e-Insaf would harm the drivers.