Fox News Senior White House correspondent, Major Garrett tweeted the details. Here’s a summary from his Twitter feed:

Deets from WH b-ground brief on Iran nuke facility: US, France, UK briefed IAEA in Vienna Thurs pm, then Russia and China today
The Iran facility issue came up in UN 1-on-1s w/Obama and Hu and Medvedev, but tech briefing happened today.
Admin says Iran not disclosing facility is “clear violation” of “safeguards agreement” that requires rpt when decision made to build plant
As 4 China (key player in any new Sec Cncl sanctions) senior ofc says “stay tuned” because Chinese just now “fully absorbing” intel.
+ deets: Iran facility NOT operational, had abt 3K centrifuges & cld produce 1 or 2 warheads if run to produce highly enriched uranium + deets. In March 2007, Iran said it didn’t have to comply w/”safeguards rpt.” IAEA (UN nuke watchdog) issued ruling denying such a move. On IAEA access to Iran facility, agency has already asked. Senior US ofc: “how quickly they get into the facility, that’s up to Iran.” Admin ofcs: Iran info out 2day bc Iran told IAEA abt it (sort of) Monday. US wanted to lay out intel w/IAEA 1st, then tell Russia, China. Also, Adm briefed elected Cong ldrshp n Iran nuke facility “in last 24 hours” and briefings cont 2day w/key nat security cmtes.