Iranian nuclear deal 'could be sunk by one-sided US changes'
Russia's foreign minister Sergey Lavrov said the landmark Iranian nuclear deal can only be amended if his country and other signatories agree to proposed changes.
Donald Trump threatened to pull America out of the deal unless the US amends the law that allows and spells out the terms of Washington's participation in the international accord.
The US president alone cannot actually terminate the 2015 agreement, which lifted sanctions which had choked Iran's economy in exchange for Tehran rolling back its nuclear programme.
Withdrawal by the US would render the deal virtually meaningless.
Speaking in Moscow, Mr Lavrov said any unilateral changes to the deal "could bury this agreement, which is vital for strategic stability and nuclear non-proliferation".