WASHINGTON - The United States on Thursday imposed economic sanctions on 11 individuals and companies accused of supporting Iran’s Revolutionary Guards or engaging in hostile cyber-attacks on US banks, the Treasury Department announced.

The move to toughen sanctions for Iran’s alleged destabilization of the Middle East contrasted with an expected decision by the White House to continue to exempt Iran from sanctions imposed on its nuclear program which America undertook to remove as its part of the landmark 2015 nuclear deal. Trump’s administration has criticized this deal, negotiated by the prior Obama administration, but has so far continued to waive the nuclear-related sanctions.

The new sanctions announced Thursday targeted an engineering company, two air transport firms and an IT company accused of carrying out denial-of-service attacks on at least nine American financial institutions, including major banks and stock exchanges between 2011 and 2012.

“Treasury will continue to take strong actions to counter Iran’s provocations, including support for the IRGC-Qods Force and terrorist extremists, the ongoing campaign of violence in Syria, and cyber-attacks meant to destabilize the US financial system,” Treasury Secretary Steven Mnuchin said in a statement. Speaking on condition of anonymity, senior administration officials told reporters on Thursday the US was pursuing sanctions on Iran in areas beyond its nuclear program but that the Trump administration would hold Tehran to its obligations under the 2015 agreement. The sanctions effectively freeze their targets out of much of the global financial system and block them from accessing assets within the US.

The alleged cyber-attacks occurred between December 2011 and December 2012, according to the Treasury Department, which said the company in question, ITSec Team, was working at the time for the Revolutionary Guards, which has been under US sanctions since 2007.

Other firms designated by the Treasury included the Sadid Caran Saba Engineering Company, which Treasury said had been under contract since as early as 2014 to install explosion-proof crane systems for the Guards’ Research and Self-Sufficiency Jehad Organization, which develops ballistic missiles for Iran and is already subject to US sanctions.

The Khors Aircompany, based in Ukraine, and Dart Airlines were also designated by the Treasury for allegedly helping provide US aircraft, as well as crew and services to Iran’s Caspian Air and Iraq’s Al-Naser Airlines, companies that are themselves already under US sanctions for supporting the Revolutionary Guards.

Additionally, the Treasury Department named seven Iranian nationals currently under indictment by a federal grand jury in New York for their alleged roles in the ITSec attacks.