US President Barack Obama said  that he took “full responsibility” for a counter-terrorism operation in January against Al Qaeda which accidentally killed two hostages.

“As president and as commander-in-chief, I take full responsibility for all our counter-terrorism operations, including the one that inadvertently took the lives of Warren (Weinstein) and Giovanni (Lo Porto). I profoundly regret what happened,” Obama told reporters.

Earlier in the day, a White House statement said that a US counter-terrorism operation in January killed the two hostages, held by Al Qaeda in the border region of Afghanistan and Pakistan, Xinhua news agency reported.

According to the statement, Weinstein was an American held by Al Qaeda since 2011, and Lo Porto was an Italian national in hostage since 2012.

“Our initial assessment indicates that this operation was fully consistent with the guidelines under which we conduct counter-terrorism efforts in the region, which has been our focus for years, because it is the home of Al Qaeda’s leadership, and based on the intelligence that we had obtained at the time, including hundreds of hours of surveillance,” said Obama.

Though stressing that intelligence about the venue as an Al Qaeda compound was accurate, Obama admitted that the US Army made a mistake by alleging that “no civilians were present”.

“What we did not know, tragically, is that Al Qaeda was hiding the presence of Warren and Giovanni in this same compound,” he said, adding that he had already directed full review into the incident.

According to the White House statement, Ahmed Farouq, an American who was an Al Qaeda leader, was also killed in the same operation that resulted in the deaths of Weinstein and Lo Porto.

A likely separate US counter-terrorism operation also killed Adam Gadahn, an American who became a prominent member of Al Qaeda.