Sri Lanka, Aug. 28 -- The UK, France and Germany have begun the process of restoring major UN sanctions on Iran - lifted under a 2015 deal - as tensions once again escalate over Iran's nuclear programme.

The move will trigger a so-called snapback mechanism, which could result in the return of sanctions in 30 days.

The three countries, participants in the 2015 deal, warned two weeks ago that they were ready to do this unless Iran agreed to a "diplomatic solution" by the end of August.

Talks between Iran and the US over its nuclear programme have not resumed since June when the US bombed Iranian nuclear sites and Iran barred UN-backed inspectors from accessing its facilities.

The snapback provision was built into the 2015 accord and all...