A senior al-Qaeda commander in Afghanistan was killed in a U.S. airstrike earlier this month, U.S. Defense Secretary Ash Carter has said, according to BBC News.

He said that Abu Khalil al-Sudani was killed on July 11.

Carter said that al-Sudani planned suicide operations, and was directly linked to plots to attack the U.S. Al-Sudani also directed operations against Nato, Afghan and Pakistani forces, Carter said, and was close to al Qaeda leader Ayman al-Zawahiri.

"Al-Sudani was one of three known violent extremists killed in the strike," a Pentagon statement said. "The death of al-Sudani will further degrade al Qaeda operations across the globe."

Carter said that the trio were killed in the Bermel district of Paktika province.

The latest violence comes amid an increase in Taliban attacks on government and foreign targets during their summer offensive.

Earlier this month, Afghan Taliban leader Mullah Mohammed Omar backed peace talks with the government. The two sides are due to meet again at the end of July, officials said on Friday, with the venue still to be decided.