Secretary of State Hillary Clinton
said Sunday the United States could not rule out using nuclear weapons
if it came under biological attack, saying in that case "all bets are off."
"If we can prove that a biological attack originated in a country that attacked us, then all bets are off," Clinton said in an interview with CBS's "Face the Nation."
Clinton was referring to a new US nuclear policy unveiled last week that restricted the use of atomic weapons against non-nuclear states that comply with the Nuclear Non-Proliferation Treaty (NPT).
Both Clinton and Defense Secretary Robert Gates said in joint television interviews that Iran and North Korea represented exceptions to the limits on a US nuclear response, as both have defied UN resolutions on their atomic programs.
"We leave ourselves a lot of room for contingencies," Clinton said.
Asked why Iran and North Korea were considered exceptions, Gates said: "Well, because they're not in compliance with the nuclear non-proliferation treaty. So for them all bets are off. All the options are on table."
Clinton and Gates said a new arms control deal with Russia and the revised nuclear policy would bolster President Barack Obama's diplomatic efforts to isolate Iran and North Korea over their nuclear programs.