Obama imposes new sanctions on Iran

US President Barack Obama has imposed new sanctions on Iran's central bank as he seeks to tighten a choke hold on the Islamic republic's ailing economy and compel it to reverse course on its nuclear program.

Obama's move, made public Monday, came as US officials warned foreign, non-American banks doing business with Tehran that they too could soon face sanctions, and amid speculation about a possible Israeli strike on Iran.

The US president tried to still some of the nervousness at the weekend, saying that he did not think Israel had taken a decision to launch a high-risk military assault on underground nuclear plants it sees as an existential threat.