Britain, France and Germany have proposed fresh EU sanctions on Iran over its ballistic missiles and its role in Syria's war, according to a confidential document, in a bid to persuade Washington to preserve the 2015 nuclear deal, which was signed by world powers and curbs Tehran's ability to develop nuclear weapons.

The joint paper was sent to European Union capitals on Friday, said two people familiar with the matter, to sound out support for such sanctions, which would need the support of all 28 EU governments.

The proposal is part of an EU strategy to save the accord by showing U.S. President Donald Trump that there are other ways to counter Iranian power abroad.