Security Council resolutions that call for the end of uranium enrichment, the closing of Fordo, the enrichment facility.

WHITEHOUSE: Press Briefing

Iran revealed the existence of the Fordo enrichment facility, which is being built about 30km (20 miles) north of Qom, in September.

BBC: Iran plays down UN nuclear report

The proposal was thought to repeat an earlier demand to stop uranium enrichment and to shut down the Fordo underground enrichment facility.

BBC: Iran nuclear crisis: Jalili says talks 'positive step'

Reuters news agency quoted Mr Jalili as saying after the talks that there was "no justification" for shutting Fordo, although he said the issue of 20% enrichment "can be discussed in the negotiations... in a view of confidence-building".

BBC: Iran nuclear crisis: Jalili says talks 'positive step'

's International Atomic Energy Agency asked Iran to explain the presence of particles of enrichment levels of up to 27%, found in an analysis of environmental samples taken in February at the Fordo fuel enrichment plant near the city of Qom.

CNN: Talks over Iran's nuclear program resume in Moscow