Matthew Lee, The Associated Press

U.S. Secretary of State John Kerry threatened Thursday to walk away from nuclear talks as he signaled that diplomats won’t conclude an agreement with Iran over the coming hours — another delay that this time could complicate American efforts to quickly implement any deal.

Negotiators at the Iran nuclear talks broke through their second deadline in a week on Tuesday, raising new questions about the ability of world powers to cut off all Iranian pathways to a bomb through diplomacy. The discussions, already in their 12th day, were prolonged until possibly Friday.

The top American and Iranian diplomats faced each other across a square table in a 19th century Viennese palace, the room austerely decorated and the atmosphere calm as they started the final push for a generation-defining nuclear agreement on Saturday.

The Obama administration may have to backtrack on its promise that it will suspend only nuclear-related economic sanctions on Iran as part of an emerging nuclear agreement, officials and others involved in the process tell The Associated Press.

Qatar has agreed to temporarily extend travel bans on five senior Taliban leaders released last year from the prison at Guantanamo Bay, Cuba, in exchange for Sgt. Bowe Bergdahl, a senior U.S. official said on Sunday.

The Obama administration is closing in on an agreement with Qatar to extend travel bans for five senior Taliban leaders released last year from the prison at Guantanamo Bay, Cuba, in exchange for Sgt. Bowe Bergdahl, U.S. officials said Friday.

The Obama administration on Friday formally removed Cuba from a U.S. terrorism blacklist as part of the process of normalizing relations between the Cold War foes.

U.S. Secretary of State John Kerry on Monday accused North Korea of a litany of crimes and atrocities while reassuring South Korea of America’s “ironclad” security commitments.

China and the United States are budging not a bit over Beijing’s assertive development in disputed parts of the South China Sea, with Chinese officials politely but pointedly dismissing Washington’s push for U.S.-proposed ways to ease tensions.

U.S. Secretary of State John Kerry is in China to press Beijing to halt what the U.S. considers increasingly assertive actions it is taking in the South China Sea that have alarmed the United States and China’s smaller neighbors.