The US Senate has overwhelmingly approved expanded sanctions on Iran’s energy, port, shipping and ship-building sectors. In a 94-0 vote, the Senate approved the new measures, proposed by Senators Bob Menendez and Mark Kirk, as part of a sweeping defense bill. The sanctions will penalize transactions with Iran’s energy, port, shipping and ship-building sectors and target individuals who sell or supply materials, such as graphite, aluminum and steel, to Iran. The measures will also slap sanctions on those who purchase Iran’s oil with precious metals, including gold, in an effort to prevent Tehran from circumventing the existing economic sanctions. “The most recent sanctions are working toward crippling Iran’s economy but Iran hasn’t quit trying,” Senator Menendez said on the Senate floor. Senator John McCain said: “The screws need to be tightened.” Reports said that the Obama administration has some concerns about the bill on the ground that it does not provide enough “waiver flexibility.” Before US President Barack Obama signs it into law, the defense bill needs to be passed by both the US Senate and House. The two chambers are now trying to work out their differences on the legislation. The United States and its Western allies have been accusing Iran of secretly developing nuclear weapons under a civilian disguise, a charge that has always been denied by Tehran. Starting from last year, the Obama administration has significantly stepped up its pressure on Iran by slapping a series of crippling economic sanctions on the Islamic republic, in a bid to stop it from advancing its controversial nuclear program. On December 31, 2011, Obama signed a bill on imposing new sanctions on Iran, targeting foreign financial institutions that do business with Iran’s central bank, the main conduit for its oil revenues.