In this Aug. 5, 2012 file photo, a Pakistani Taliban militant holds a rocket-propelled grenade at the Taliban stronghold of Shawal, in the Pakistani tribal region of Waziristan, Pakistan. (Ishtiaq Mahsud/AP)

Obama administration officials confirmed Wednesday that the military operations commander of the Taliban-allied Haqqani militant network was killed by a U.S. drone-fired missile last week in Pakistan.

Badruddin Haqqani was the third-ranking official of the militant group, which the administration considers the most potent threat to U.S. efforts in Afghanistan, and the most senior member killed to date. His father, Jalaluddin Haqqani, founded the network and remains its titular head, and his brother, Sirajuddin, is its current leader.

Afghan officials had previously said that Badruddin was killed in one of at least six reported drone strikes since Aug. 18 in North Waziristan, a Pakistani tribal area that borders Afghanistan, but U.S. officials had said they were still trying to confirm the report.

“We now believe he is dead,” an administration official said on condition of anonymity to discuss intelligence matters. A spokesman for the CIA, which operates the drone program in Pakistan, declined comment.

The administration considers Badruddin Haqqani responsible for planning a series of increasingly high-profile attacks in Afghanistan, including last September’s assault on the U.S. Embassy compound in Kabul.

Following that attack, the administration publicly escalated allegations of direct ties between the Haqqani network and Pakistan’s Inter-Services Intelligence agency, and warned of an escalation of direct action against the Afghan militant group’s haven in North Waziristan.

This month’s drone strikes mark the most sustained attacks since Pakistan agreed on July 3 to reopen its border crossings for the transit of supplies to U.S. and NATO troops in Afghanistan. The border was closed last November after 24 Pakistani soldiers were killed in a cross-border U.S. air strike.

Pakistan demanded, and eventually got, a U.S. apology for the deaths. But the seven-month diplomatic standoff also led to renewed Pakistani demands to stop drone strikes in its territory. That issue remains under discussion between the two governments.

Pakistan has repeatedly denied U.S. charges of close ties with the Haqqani network, but a long-awaited Pakistani military offensive against the group’s North Waziristan sanctuary has never materialized.

Although individual network leaders, including Badruddin Haqqani, have been designated as terrorists by the State Department, the group itself has not been. Last month, Congress passed legislation giving the State Department 30 days to add the Haqqani network to the list of designated foreign terrorist organizations or explain why it would not do so.

Haqqani forces were part of the fight against Soviet occupation of Afghanistan in the 1980s and were among those groups receiving aid from both Pakistan and the United States. Jalaluddin Haqqani later became an official in the Taliban government that took over Afghanistan in 1996, and he fled to the Pakistani tribal region, along with al-Qaeda, after the Taliban was overthrown with U.S. assistance in 2001.

Haqqani fighters regrouped and began fighting U.S. and coalition forces across the border in Afghanistan.