"We'll be doing a snapback," the president said, referring to the contested argument that the US remains a "participant" in the 2015 Iran nuclear deal -- despite Trump's withdrawal from it -- and therefore can force a return to sanctions if it sees Iran as being in violation of its terms.

The president added that the US will make its move next week.

Washington's defeat at the Security Council on Friday highlighted its isolation on Iran since Trump withdrew from the accord in 2018.

Only two of the Council's 15 members voted in favor of the US resolution.

Washington's European allies all abstained, Russia and China voted against it, and Iran mocked the Trump administration for winning the support of just one other country, the Dominican Republic.

Trump argued Saturday that Iran was a "different ballgame" now, and that the country no longer has the funds to sponsor terror.

"Iran wants me to lose so badly" in November's presidential election, he added.

If Trump follows through, the snapback could plunge the Council into one of its worst-ever diplomatic crises, experts warn.

European allies have been skeptical on whether Washington can force sanctions and say the attempt may delegitimize the Security Council.

The embargo on conventional arms is due to expire on October 18.