The Trump administration re-imposed sanctions this month after withdrawing from the 2015 international nuclear deal with Iran, which Washington saw as inadequate for curbing Tehran's activities in neighbouring Middle East countries.
Secretary of State Mike Pompeo said that the Trump Administration want neither Iran nor North Korea to have the capacity to proliferate nuclear weapons, to enrich uranium or build their own weapons programme.
Former US Secretary of State John Kerry, who led President Obama's efforts to broker the Iran nuclear deal, cautioned that a "new arms race" was taking place and endangering other weapons reduction treaties.
Donald Trump has backed away from a campaign promise to scrap a major nuclear security deal with Iran. The Trump administration faced a new congressional deadline yesterday to say whether Iran has curbed its nuclear weapons program in line with the accord.