The U.S. Treasury Department on Friday penalized more than 25 entities and individuals it believes are involved in assisting Iran’s nuclear program, supporting terrorism or aiding Tehran’s evasion of U.S. and international sanctions.

“Today we took additional steps in our effort to maintain pressure on Iran,” White House National Security Council spokeswoman Caitlin Hayden said in a statement.

She said the new penalties were an effort to enforce sanctions that existed against Iran before the United States and five other partner countries began negotiating with Tehran to try to roll back parts of its nuclear program.

She said the U.S. actions Friday are “consistent” with commitments made in this year’s talks with Iran to provide limited sanctions relief in exchange for Iranian steps that “halted its nuclear program and rolled it back in key respects.”

The new sanctions bar certain companies from doing business with people in the U.S., the Treasury Department said in a statement.

The targeted companies include: the Organization of Defensive Innovation and Research, a Tehran-based company primarily responsible for researching nuclear weapons development; the Nuclear Science and Technology Research Institute, which implements projects in the nuclear field, specifically at Iran’s heavy water research reactor in Arak; Jahan Tech Rooyan Pars and Mandegar Baspar Kimiya Company, two Iran-based businesses involved in the procurement of “proliferation-sensitive” material.