The top U.S. military officer is visiting Pakistan at a time of tensions over America's role in the region.
The U.S. Embassy says Adm. Mike Mullen, chairman of the Joint Chiefs of Staff, will spend Wednesday and Thursday meeting with Pakistani leaders.
Mullen is a frequent visitor to Pakistan, and reportedly has a good relationship with Pakistan's army chief, Gen. Ashfaq Parvez Kayani.
The United States needs Pakistan's cooperation to help end the war in Afghanistan.
But tensions between the two allies have spiked this year after an American CIA employee shot and killed two Pakistanis he said were trying to rob him.
A March missile strike ostensibly targeting the Taliban also angered Kayani, who said dozens of innocent tribesmen were killed.