The administration has made “an extraordinary effort” to put together an international consensus on the stricter sanctions, Tierney said.
He added that the most recent batch of U.N. economic sanctions on Iran appear to have slowed the country’s nuclear weapons work.
Acting Deputy Assistant Secretary of State Henry Wooster told the subcommittee in written testimony that sanctions “are having an effect.” He cited comments by Iranian President Mahmoud Ahmadinejad that the U.N. sanctions have proved “the heaviest economic onslaught on a nation in history.”
Tierney also cautioned his fellow lawmakers against passing legislation that would require the United States to slap unilateral economic sanctions on Iran in an effort to change the regime’s behavior.
Some lawmakers have pushed the notion of unilateral sanctions — or even using U.S. military force to halt Iran’s nuclear program.
The president needs to retain his office’s traditional leverage and flexibility to tailor and use sanctions within the international community, Tierney said.
The ranking member called for other nations to join with Washington in imposing “narrowly defined” economic sanctions that target Iranian leaders.
Analysts from several think tanks told the subcommittee that tougher Iran sanctions could have an effect, but are unlikely to deter Tehran from building nuclear arms.