The international financial transaction system known as the Society for Worldwide Interbank Financial Telecommunication, or SWIFT, will disconnect access from the Central Bank of Iran, according to U.S. Treasury Secretary Steve Mnuchin.

“I understand that SWIFT will be discontinuing service to the Central Bank of Iran and designated Iranian financial institutions,” Mnuchin posted on Twitter on Thursday. “SWIFT is making the right decision to protect the integrity of the international financial system.”

This development comes as SWIFT announced on Monday it is “suspending certain Iranian banks’ access to the messaging system” after U.S. sanctions were reimposed on Nov. 5. They had been lifted under the 2015 Iran nuclear deal, which America exited in May.

“In keeping with our mission of supporting the resilience and integrity of the global financial system as a global and neutral service provider, SWIFT is suspending certain Iranian banks’ access to the messaging system,” SWIFT announced.

The Belgium-based organization noted that “this step, while regrettable, has been taken in the interest of the stability and integrity of the wider global financial system.”

Iran will still be able to access SWIFT for solely humanitarian purposes, said Treasury Secretary Steve Mnuchin last week in a conference call with reporters.

“Humanitarian transactions to non-designated entities will be allowed to use the SWIFT messaging system as they have done before,” he said, “but banks must be very careful that these are not disguised transactions, or they could be subject to certain sanctions.”