Iran's foreign minister says his country will continue nuclear negotiations with world powers, even after pulling out of expert-level talks to protest the U.S. targeting companies it says evaded current sanctions.

Foreign Minister Mohammad Javad Zarif made the comments in a Facebook post early Sunday morning. He blamed "improper actions" by the U.S. for Iran pulling out Friday.

Zarif wrote: "We will continue Geneva talks. We will show proper, calculated, purposeful and smart reaction toward any improper and unconstructive action."

He also wrote: "Talks and reaching a conclusion is a difficult job and it will definitely have ups and downs. ... We had predicted this from the first day."

The West fears Iran's nuclear program could allow it to build nuclear weapons. Iran says its program is for peaceful purposes.