"We urge you to take all necessary steps to ensure the Society for Worldwide Interbank Financial Telecommunication (SWIFT) disconnects the Central Bank of Iran (CBI) and all other designated Iranian financial institutions," the lawmakers said.
The senators said the Trump administration’s maximum pressure campaign against Iran will not succeed if the Iranian government remains connected to the SWIFT.
The United States has authority to take such decisive action against Iran under Section 220 of the Iran Threat Reduction and Syria Human Rights Act of 2012, the senators noted.
READ MORE: 'Independent SWIFT' Issue Amid US Sanctions Shows EU Colossus With Feet of Clay
The letter was signed by Senators Marco Rubio, Tom Cotton, John Barrasso, Mike Rounds, Ben Sasse, Roger Wicker, Cindy Hyde-Smith, Todd Young, Ron Johnson, Cory Gardner, Mike Enzi, Thom Tillis, Johnny Isakson, David Perdue, and Steve Daines.
Iran is currently facing the reintroduction of US sanctions. The initial round of sanctions went into force earlier this month, while the second round is expected to take effect in the fall.
READ MORE: EU Sees Idea to Create 'Independent SWIFT' to Secure Iran Deal - Source
In May, US President Donald Trump said that the United States would leave the nuclear agreement with Iran that stipulated Tehran should ensure the peaceful nature of its nuclear program in exchange for the gradual lifting of sanctions.