WASHINGTON - The United States is targeting more than 25 businesses, banks and individuals suspected of working to expand Iran's nuclear program, supporting terrorism and helping Iran evade U.S. and international sanctions.

The Treasury Department's action on Friday is part of the Obama administration's effort to show it will enforce existing sanctions even as it negotiates a deal to curtail Iran's nuclear program.

As a result of the action, Americans are banned from engaging in transactions with any of the designated parties and blocks all their property or interests in property under U.S. jurisdiction.