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The proposed sanctions build on penalties signed into law by President Barack Obama in December that have made it difficult for Tehran, the world's third-largest petroleum exporter, to sell its oil, in a bid to cut the flow of revenues suspected of supporting the nuclear program. The move comes ahead of negotiations beginning next week in Baghdad between Iran and six world powers about Tehran's nuclear program.
"Iran must either willfully commit to terminating its nuclear program or we will force their hand through crippling sanctions," said Democratic Senator Robert Menendez, chief architect of the sanctions.
Tehran is seeking sanctions relief at the talks, but passing the Senate bill will show the US has political support to intensify sanctions, said Mark Dubowitz, head of the Foundation for Defense of Democracies, and an advocate for tougher sanctions on Iran.
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