FREEZE ON FOREIGN RESERVES
The United States has long barred American firms from doing business with Iran. In December, the government adopted measures authored by Kirk and Democratic U.S. Senator Robert Menendez that force international buyers of Iranian oil to cut their purchases.
Last week, Menendez said in an interview that he was working on a bill to impose new penalties on foreign banks that handle any significant transactions with Iran's central bank.
Menendez said he is also looking at ways to freeze an estimated 30 percent of Iran's foreign currency reserves held in banks outside the country.
Projections by one sanctions advocacy group, the Foundation for Defense of Democracies, suggest that Iran has at least two years' worth of foreign exchange reserves to help support its economy, said the group's executive director Mark Dubowitz
New measures proposed by Congress could limit access to those reserves, further limit Iran's ability to access foreign goods and services, and encourage capital flight, Dubowitz said.
"I think Congress is trying to come up with a series of measures that can have a dramatic and profound impact on Iran's balance of payments without imposing a formal trade embargo on Iran," he said.
"The risk is that it ends up being too little, too late," he said.
U.S. Defense Secretary Leon Panetta said on Saturday that the international community will impose more economic sanctions on Iran if the country does not resolve concerns over its nuclear program.