By Roberta Rampton
WASHINGTON (Reuters) - The U.S. Senate is set to consider a broader set of economic sanctions on Iran's energy, port, shipping and shipbuilding sectors, as lawmakers look for new ways to pressure Tehran to stop efforts to enrich uranium to levels that could be used in weapons.
It is the third time in a year that U.S. lawmakers have looked for new ways to cut off revenues they believe fund Iran's nuclear program, which Tehran has said is strictly for civilian purposes.
The sanctions come as the United Nations' nuclear chief said his agency has made no progress in its year-long push to investigate whether Iran has worked on developing an atomic bomb.
Iran's economy has been badly damaged by sanctions by the United States and European Union, but Iran has not slowed its program, said Senator Robert Menendez, a New Jersey Democrat who helped craft the new proposal.
"We will send a message to Iran that they can't just try to wait us out," Menendez said in a statement.
The new sanctions were filed as an amendment to an annual defense policy bill. Senators were expected to continue to debate other parts of the massive bill late into Thursday night, and it was not clear precisely when the Iran sanctions measure would be considered.
Republican Senator Mark Kirk of Illinois, who co-authored the package, said in a statement the sanctions would turn up pressure on Iran's government. Kirk and Menendez last year championed new sanctions that curbed Iran's oil exports.
"We have a responsibility to do everything in our power to put crippling pressure on the Iranian government, and passing these new sanctions is absolutely critical to that effort," said Senator Joseph Lieberman of Connecticut, an independent, who co-sponsored the new bill.
The new sanctions also blacklist trade in a list of commodities including precious metals, and aluminum and steel used in the shipbuilding and nuclear sectors, matching EU measures, said Mark Dubowitz, the head of the Foundation for Defense of Democracies, who has pushed for stronger sanctions on Iran.
"We must find new ways to increase the pressure and stop Iran from acquiring a nuclear weapons capability," Dubowitz said in a statement.
(Reporting by Roberta Rampton; Editing by Sandra Maler and Eric Beech)