The White House says two Western hostages were killed in a U.S. antiterrorist operation near the Afghan-Pakistani border in January.
President Barack Obama expressed his "tremendous sorrow" that the operation ended in the deaths of the two hostages, one of whom was a U.S. citizen and the other an Italian being held by the Al-Qaeda terrorist network.
Obama said: "Our hearts go out to the families of Dr. Warren Weinstein, an American held by Al-Qaeda since 2011, and Giovanni Lo Porto, an Italian national who had been an Al-Qaeda hostage since 2012."
He said: "No words can fully express our regret over this terrible tragedy."
A White House statement said the two died when U.S. intelligence targeted the compund they were being held in without knowing the hostages were there.
Ahmed Farouq, a US citizen who had become an Al-Qaeda leader, was killed in the same operation. Another U.S. citizen turned Al-Qaeda terrorist, Adam Gadahn, was killed in a separate operation in January.
Obama said he took "full responsibility" for the deaths and said he wanted to "provide the American people with as much information as possible about our counterterrorism operations, particularly when they take the lives of fellow citizens."
Based on reporting by dpa, AP, and Reuters