The symbolic measure aimed at building pressure on Iran as nuclear negotiations have entered a sensitive stage was approved on Thursday with 100 votes in favor of the motion and zero against it.
Republican Senator Mark Kirk introduced the amendment, which was part of an ongoing budget debate. The measure is non-binding because budget resolutions do not become law, but it was passed to send a political message.
"If we find out that there's further development in the Iran nuclear program, it will allow me to remind 100 senators that they voted with me today," Kirk told the AFP news agency.
The 100 percent support for the measure came after it was amended. The original document supported restoring removed sanctions as well as imposing new sanctions, if Iran violated an agreement on its nuclear energy program.
The amendment supports imposing sanctions against Iran if Obama "cannot make a determination and certify that Iran is complying" with a nuclear accord.
The Senate vote comes at a time when officials from Iran and the P5+1 – the US, Britain, France, China, Russia and Germany – have resumed sensitive negotiations in Switzerland aimed at reaching a comprehensive agreement in order to end the longstanding dispute over the Islamic Republic’s civilian nuclear work as a July 1 deadline approaches.
Representatives of Iran and the P5+1 took part in the talks in the Swiss city of Lausanne on Thursday.
Following the deputy-level talks, Iranian Deputy Foreign Ministers Abbas Araqchi and Majid Takht-e Ravanch also held a separate meeting with their Russian counterpart Sergey Rybakov.
Before the meetings, representatives of Iran, the US and the European Union ended a second round of nuclear talks on Tehran’s nuclear program.