Biden was due to meet president Asif Ali Zardari and prime minister Yusuf Raza Gilani, said a senior Pakistani government official, who said a third meeting was likely to take place with Gen. Ashfaq Kiyani, the army's chief of staff.
Biden's visit came just hours after a U.S. counterterrorism official told CBS News correspondent Bob Orr that an American missile strike had killed two senior al Qaeda figures in Pakistan.
The men were identified as Usama al-Kini, al Qaeda's operations chief in Pakistan, and Sheikh Ahmed Salim Swedan, a top lieutenant.
A senior Pakistani security official confirmed the killing of the two militants, saying Pakistan had, "knowledge of the killing," but declining to give further details on the grounds that it would compromise important security information.
Al Kini and Swedan, "were very high on our list of people that we (U.S. and Pakistan) wanted to catch," said the Pakistani security official.
A Senior Western diplomat said it was important to note that confirmation of the killings coincided with Biden's visit. It's not the first time the arrest or killing of important terror suspects linked to Pakistan has come just as senior U.S. officials visit the country.
"The Pakistanis will be keen to impress Mr. Biden, who will be a key figure in the next U.S. administration, that they are vital players in the war on terror," said one Western diplomat in Islamabad, who, like the other sources, did not want to be named.
Bruce Hoffman, a terrorism expert at Georgetown University, told the Washington Post that the targeted strikes by U.S. drones appear to be hitting al Qaeda's senior members hard, and it could be thanks to the Pakistanis.
"It is a stunning testament of the accuracy of intelligence that the United States is obtaining," Hoffman told the paper. "Either we have built up an impressive network of sources that facilitates such precision targeting, or the Pakistani authorities are cooperating big-time." (Click here to read the Washington Post's article.)
Pakistani officials expect Biden to visit India during his current trip to meet Indian Prime Minister Manmohan Singh, in an attempt to bridge differences between the two south Asian nuclear-armed countries following the November 2008 terrorist attacks in Mumbai.