The US Senate will vote this week on legislation to renew sanctions on Iran for 10 years, Majority Leader Mitch McConnell said.
"Preserving these sanctions is critical given Iran's disturbing pattern of aggression and its persistent efforts to expand its sphere of influence across the Middle East," McConnell said on Tuesday.
The House of Representatives voted 419 to 1 last month to reauthorize the Iran Sanctions Act (ISA), which was first introduced in 1996 to punish investments in Iran's energy industry based on accusations that Tehran was pursuing non-civilian objectives in its nuclear energy program.
If the House bill is passed in the Senate as expected, it would be sent to the White House, where President Barack Obama is expected to sign it into law. The act is set to expire at the end of 2016.
Iran and the five permanent members of the UN Security Council -- the United States, Britain, Russia, China, France as well as Germany – reached a landmark nuclear agreement last year, under which Tehran agreed to limit some aspects of its nuclear program in exchange for removal of all sanctions.
The two sides began implementing the deal, dubbed the Joint Comprehensive Plan of Action (JCPOA), on January 16.
However, members of Congress said they wanted the ISA to be extended for another decade to send a strong signal that any US president would have the ability to “snap back” sanctions on Iran.
"Unless Congress acts, the congressional sanctions don't exist after December 31," Maryland Senator Ben Cardin, ranking member on the Senate Foreign Relations Committee, told The Weekly Standard on Tuesday. "The ability to snap back wouldn't be there on the congressional side."
White House officials have indicated that the reinstatement of sanctions was not needed, but said sanctions are technically allowed under the nuclear accord.
Iran has warned that the renewal of sanctions will be a violation of commitments under the JCPOA, and has threatened reprisal if the US extends the longstanding act.
On Monday, Ali Akbar Salehi, the head of the Atomic Energy Organization of Iran, said Tehran has made necessary preparations and is ready to respond if the US violates the deal.
Sen. Cardin dismissed Iran’s warnings as unfounded. "Iran is making this up. These problems don't exist."
"Congress, by extending ISA, is not taking any new steps against Iran at all," he stressed.