The head of Russia's Atomic Energy Agency, Sergei Kiriyenko, has returned from from Tehran, saying talks about a compromise to end the crisis over Iran's nuclear program will continue later this week in Moscow.

An Iranian delegation is expected in Moscow this week for a third round of talks on a compromise proposal for Russia to enrich Iran's uranium. The effort is an attempt to ease western concerns over Iran's nuclear program and to avert possible punitive sanctions against Tehran.

The head of Russia's Atomic Energy Agency, Sergei Kiriyenko, completed three days of, what he called, complicated, difficult negotiations with Iranian officials in Tehran. Reports coming out of the closed-door talks are sketchy, with no confirmation that Iran has agreed to suspend enrichment as required by the United States and Europe.

But Kiriyenko told Russia's Itar-Tass news agency he is certain enough time remains to seal a deal.

Others, like independent expert Vladimir Yevseyev, of Moscow's Carnegie Institute, are not so optimistic. Yevseyev tells VOA he thinks Iran is just stalling for time before the March 6th meeting of the International Atomic Energy Agency, during which a decision is expected to be made on possible punitive sanctions over Iran's nuclear program.

"I think really Iranian officials want to continue these negotiations without any decisions and maybe its good for Iran, but it is very bad for the other countries," he said.

Yevseyev says Russia, as the sole moderator, risks losing influence if the talks continue much longer without definitive word of progress or take a turn for the worse.

"It is a good idea for Russia to stay [with] Iran like a partner," said Yevseyev.  But if Iran will provoke the west, and if Iranian leaders will speak about Israel [and that] it is necessary [for it] to disappear, and speak about passing nuclear technology to other countries, [then] it is very difficult for Russia to stay on the position [of being] like a friend to Iran. Russia's position will be moved to the west."

Independent Military analyst Alexander Goltz shares Yevseyev's skepticism surrounding continued talks.

"We have example of North Korea, which was extremely successful in organizing absolutely endless talks, which permitted North Korean leaders to practically blackmail world leaders and all international society," said Goltz. "I think Iranian leaders have the same goal. They badly need time."

In Washington, National Security Advisor Stephen Hadley reacted cautiously to reports from Tehran of basic agreement on the compromise proposal. Hadley told the U.S. CNN it is necessary to wait and see what happens next.