US Republicans said Tuesday they were introducing legislation that would use frozen Iranian assets to pay American victims of Iranian terrorism before billions of dollars are returned to Tehran as part of the nuclear deal.
Congressional Republicans are furious over President Barack Obama's landmark accord with world powers that aims to rein in Iran's nuclear program, in exchange for an easing of sanctions that have crippled the Islamic republic's economy.
They see the Justice for Victims of Iranian Terrorism Act as a way to stall the deal, or at least take a major bite out of funds that would be returned to Tehran.
The bill will be introduced this week, according to its sponsor, House Republican Pat Meehan.
"There are some $43.5 billion in judgments which have been rendered under American law for victims of acts of Iranian terror," with more than 80 lawsuits successfully prosecuted through US courts, Meehan told reporters.
"Despite this, not one cent has been paid by Iran," he said. "This is an opportunity to change that dynamic."
In backing the bill, House Speaker John Boehner said it would be unfair for Obama to "provide Iran with about $100 billion of their assets locked up in Western banks, without first paying the victims of Iranian terrorism."
Meehan said he had virtually unanimous support in his caucus, and expected the measure also to be introduced this week in the Senate, where its fate remained less certain.
Sarah Shourd, who was captured while hiking along the Iran-Iraq border and imprisoned by Iran for more than a year, said the legislation would jeopardize the nuclear deal, as well as the fate of Americans currently held in Iran.
"Such an unrealistic restriction would not lead to release for the hostages or justice for victims of terrorism," Shourd wrote in Tuesday's Roll Call.
"Threatening the president's ability to provide sanctions relief threatens the deal itself."
US courts have awarded vast sums to victims' relatives who have accused Iran's government of sponsoring terrorist activities around the world.
Iran has refused to pay, and extracting the compensation has remained a challenge.
Last year a US appeals court in New York ordered that $1.75 billion in Iranian funds held in Citibank be handed over to families of Americans killed in the 1983 attack on a barracks in Beirut.
The Iranian central bank has petitioned the US Supreme Court for a review of the case.