Iran's President Hassan Rouhani has called Western sanctions an "invasion" after Washington imposed penalties on 25 businesses, banks and individuals.

Speaking to officials on Saturday, Rouhani said "sanctions are an invasion of the Iranian nation. We should resist the invasion and put the invaders in their place." His remarks were broadcast by state TV.

On Friday the United States imposed existing sanctions on more than 25 businesses, banks and individuals suspected of working to expand Iran's nuclear program, support terrorism and help Iran evade U.S. and international sanctions.

Western nations have long suspected Iran of covertly seeking a nuclear weapons capability alongside its civilian program, charges denied by Tehran.