NATO

U.S. officials confirmed they carried out the strike, but declined to say whether they killed the leader.

The strike in Nangarhar province killed Islamic State affiliate leader Hafeez Sayeed and others on Friday, said Abdul Hassib Sediqi, a spokesman for Afghanistan's National Directorate of Security. 

Sediqi said Afghan intelligence officials provided information to U.S. forces, who carried out the strike.

Stoltenberg called Greece "a staunch ally and a committed ally" on Thursday. He said the Greek government stands by its "commitments in the alliance. This good for Greece and good for NATO."

Defense Secretary Ash Carter made the announcement on Tuesday.

Carter's announcement, made as he stood with defense chiefs from Estonia, Latvia and Lithuania, comes a day after he announced that the U.S. would be contributing weapons, aircraft and forces, including commandos, as needed for NATO's new rapid reaction force, to help Europe defend against potential Russian aggression from the east and the Islamic State and other violent extremists from the south.