The resolution calls on Tehran to provide inspectors from the International Atomic Energy Agency (IAEA) with access to two sites in Iran in order to clarify whether undeclared nuclear activity took place there in the early 2000s.

Iran has been blocking access to the sites for months.

Earlier this week Iran warned that such a resolution would be "counterproductive" and that it would take "appropriate measures" in response.

Even though the sites in question are not thought to be directly relevant to Iran's current nuclear programme, the agency says it needs to know if activities going back almost two decades have been properly declared and all materials accounted for.

Despite the row over the two sites, the IAEA says it still has the access it needs to inspect Iran's declared nuclear facilities, as the agency is mandated to do under the landmark deal between Iran and world powers reached in 2015.

However the latest row comes as that deal continues to unravel, with Iran continuing to breach the limits on nuclear activity in the accord in retaliation for the United States' withdrawal from it and reimposition of sanctions.