Iranian President Hassan Rouhani has criticised the US for new sanctions, saying they are "not compatible" with the spirit of current negotiations.
Speaking on Iranian TV, he said Iran was still committed to continuing nuclear talks with the US and five other international powers.
New sanctions on 25 firms and individuals were announced in Washington on Friday.
World powers suspect Iran seeks atomic weapons, a claim it strongly denies.
The country insists that it is enriching uranium for use in nuclear power stations and for medical purposes.
The new sanctions target those suspected of evading previous sanctions, aiding the nuclear programme or supporting terrorism, US officials said.
Speaking at a news conference broadcast on state TV, Mr Rouhani said the introduction of new sanctions was "a very ugly move" that would deepen distrust between the two sides.
Bakudaily.Az