An EU spokesman says six world powers have begun talks with Iran in Moscow with an appeal for the Iranian side to “engage seriously” with an offer to resolve international concerns about the Iranian nuclear program.

Speaking to VOA by phone from the Russian capital, Michael Mann said the five permanent members of the U.N. Security Council plus Germany hope Iran “finally” will negotiate on the proposals they made in the previous round of talks in Baghdad last month. EU foreign policy chief Catherine Ashton is representing the world powers in the talks, which resumed Monday in Moscow. The two sides have made little progress since an April meeting that ended a 15-month break in negotiations.

The world powers have been pressing Iran to stop enriching uranium to 20 percent purity, a level that some see as a short-step from the higher purity needed for nuclear weapons. The six-nation group also has been calling for Iran to remove stockpiles of highly-enriched uranium from its territory and shut down an underground facility at Fordo that has been producing the material.

In return, the world powers have offered to send Iran nuclear fuel for its medical research reactor and badly-needed spare parts for its aviation industry. Iranian leaders have dismissed such offers in the past as insufficient.

Iranian President Mahmoud Ahmadinejad told a German newspaper that Iran may accept a compromise on enrichment. In excerpts of the interview published Monday on his website, Mr. Ahmadinejad said that if European nations provide Iran with 20 percent enriched fuel, his government is ready to stop enrichment to that level.

Iran says its enrichment work is for peaceful uses including electricity generation and medical research. But, Israel and Western powers accuse Iran of trying to develop nuclear weapons under cover of a civilian energy program.

An Iranian delegate in Moscow told Iran's state-run news agency IRNA that the new talks will fail if the world powers do not recognize what Tehran sees as its right to enrich uranium. The Iranian diplomat also said Iran will not agree to further negotiations unless the six-nation group accepts a five-point Iranian proposal offered in Baghdad.

EU spokesman Mann said the Iranian plan calls for discussing a broad range of issues far removed from the nuclear dispute. He said the six-nation group is “willing to respond” to the Iranian ideas but said they fall short of what he called the “concrete” proposals of the world powers.

“We haven't seen engagement on the Iranian side yet,” Mann said. “We're not prepared to talk for the sake of talking, we need to drive things forward. We know things aren't going to happen overnight but we can at least get some momentum going if the Iranians are prepared to engage on the proposals we made.”

The Moscow talks are scheduled to end Tuesday, but Mann said the world powers are “ready to stay if there is something to talk about.”

The United States and European Union have been increasing pressure on Iran to compromise by tightening unilateral sanctions targeting Iranian oil exports, a major source of the nation's income. A complete EU embargo on Iranian oil is set to begin on July 1, while Washington plans to launch sanctions on businesses dealing with Iran's oil industry several days earlier.

Russia hopes the new talks will achieve enough progress to lead to more negotiations and prevent a diplomatic failure that could lead to foreign military intervention in Iran, a longtime economic partner of Moscow.

Israel sees a nuclear-armed Iran as a threat to its existence and has hinted that it could strike Iranian nuclear sites within months to remove that threat. World powers have expressed concern that an escalation of the dispute into a regional war would trigger a jump in oil prices and depress the fragile global economy.