BAGHDAD — Iran and six nations ended two days of “intense” and difficult nuclear talks in Baghdad late Thursday with no breakthroughs but a plan to meet again in Moscow next month.

Chief European Union negotiator Catherine Ashton said that while the discussions made it clear that while “we both want to make progress and that there is some common ground … significant differences remain.”

The talks focused on a proposal from the five permanent members of the UN Security Council plus Germany — the so-called P5+1 — aimed at ending Iran's enrichment of uranium to 20%. The proposal — an updated version of a package Iran accepted then rejected in 2009 — included fuel for a vintage US reactor that produces medical isotopes for 800,000 Iranian cancer patients, safety upgrades for the reactor and for Iran’s lone civilian nuclear power plant at Bushehr plus spare parts for Iran’s ancient Boeing airliners. 

In return, Iran was asked to stop enriching uranium to 20% U-235, send out its stockpile of more than 100 kilograms of that uranium and eventually close operations at a plant dug into a mountain near the holy city of Qom. European sanctions preventing the purchase of Iranian oil as of July 1 would go forward.