By Roberta Rampton and Susan Cornwell
WASHINGTON (Reuters) - The U.S. Senate gave unanimous approval on Monday to a package of new economic sanctions on Iran's oil sector just days ahead of a meeting in Baghdad between major world powers and Tehran.
The West suspects Iran is working to build a nuclear bomb and the sanctions are meant to strip Tehran of revenue by shutting down financial deals with Iran's powerful state oil and tanker enterprises. Iran has said its nuclear program is for civilian purposes.
The House of Representatives passed its version of the bill in December and now the Senate and House must work out their differences in the legislation.
But by passing the bill ahead of the Baghdad meeting, the Senate has shown Iran that "buying time ... is just not going to work," Robert Menendez, the Democratic senator who helped craft the legislation, said on the Senate floor.
The new sanctions build on penalties signed into law by President Barack Obama in December against foreign institutions trading with Iran's central bank. Those sanctions already have cut deeply into Iran's oil trade.
The new package would extend sanctions to cover dealings with the National Iranian Oil Co and National Iranian Tanker Co, aiming to close a potential loophole that could have allowed Tehran, the world's third-largest petroleum exporter, to continue selling some of its oil.
The Senate bill was brought up on Thursday but was blocked by Republicans who wanted some parts toughened up. Senator John McCain said the revised bill shows "we need a comprehensive policy" to include economic sanctions, diplomacy, military planning capabilities and options.
(Reporting by Roberta Rampton and Susan Cornwell; Editing by Bill Trott)