Six world powers holding nuclear talks with Iran in Baghdad agreed Thursday to hold another round of negotiations in Moscow next month.

EU foreign policy chief Catherine Ashton made the announcement after a two-day meeting that she said achieved some common ground despite remaining differences. She said the Moscow talks will take place on June 18 and 19.

Ashton held a bilateral meeting with Iran's chief negotiator Saeed Jalili earlier in the day.

At issue is Iran's enrichment of uranium to 20 percent purity.

Western powers want that activity to stop, fearing Iran could quickly upgrade its uranium to the 90 percent purity needed for nuclear weapons. Iran wants an easing of international sanctions in return for any concession on enrichment work, which it says is meant for medical research and generating electricity.

EU spokesman Michael Mann told VOA the world powers presented a “clear” proposal calling on Iran to address international concerns about its nuclear program in return for “reciprocal measures” that the six-nation group believes will be attractive to Tehran. He said it is important for Iran to engage in the negotiations “seriously.”

Iran's delegation in Baghdad offered its own proposal for ending the dispute. Iranian state media said Thursday the delegation received no response to its offer despite responding to the proposal of the six-nation group.

The Iranian reports also said Iran's proposal is more comprehensive than that of the world powers and accused the United States of being unwilling to express a position on it.

Mann denied the Iranian claim, saying the world powers have responded to Iranian proposals as part of a normal negotiation process.

The world powers include the five permanent members of the U.N. Security Council plus Germany.

Diplomats say the group has offered Iran incentives to stop production of highly-enriched uranium and transfer the material abroad in exchange for nuclear fuel for its research reactor in Tehran.

Iranian diplomats have expressed disappointment with that offer, complaining that it makes too many demands of Iran without enough benefit.

In an interview with VOA, Middle East analyst Shahram Akbarzadeh said Iran may make a few concessions in a bid to ease economic sanctions.

“If by giving in to the international community slightly, if by taking one step back allows the sanctions to be cancelled then Iran would do that. But I don't think you can expect Iran to be fully cooperative with the international community.”