The U.S. secretaries of state and defense and their Russian counterparts say experts from the two countries will seek to narrow differences over a series of strategic issues that the ministers failed to resolve during face to face talks in Moscow. VOA Correspondent Peter Fedynsky reports from the Russian capital.

The meeting itself did not resolve a range of difficult strategic issues that divide Russia and the United States.

One of the most difficult is Russia's continued opposition to an American plan to deploy a missile defense system on Polish and Czech territory to guard against possible attack from Iran.

Russia sees the move as a threat, and insists Iran does not have a missile that could reach the United States. Russian Foreign Minister Sergei Lavrov said U.S. and Russian experts will seek to develop criteria to assess any Iranian threat. And, he expressed confidence that no missile defense system will be needed.

U.S. Secretary of State Condoleezza Rice, however, said the U.S. will not freeze moves toward deployment.

"The United States is engaged with discussions with our allies, and those will continue," said Rice. "We will work during this time to address Russian concerns about the nature of the system, about what is not yet a shared view of the missile threat. We believe we can address those concerns and are prepared to do it."

U.S. Defense Secretary Robert Gates used the talks to again try to reassure Russia that it should not perceive the system as a threat, but Foreign Minister Lavrov did not budge.

Minister Lavrov says Gates acknowledged Russian concerns of a potential threat from the system. He also repeated statements made by other Russian officials that his country will need to take steps to neutralize the threat.

Russian President Vladimir Putin met with his foreign and defense ministers and the visiting U.S. secretaries before their talks. Mr. Putin warned that the Russian side may abandon the Intermediate-Range Nuclear Forces Treaty with the United States, if other countries that have developed such weapons are not brought under its terms. When it was adopted in 1987, the so-called INF treaty prohibited medium range nuclear weapons, which only the former Soviet Union and the United States had at the time.

Secretary Gates expressed concern about Mr. Putin's threat to pull out of the Conventional Forces in Europe Treaty in a dispute involving a Western demand for Russia to pull its troops out of Moldova and Georgia. This issue was not resolved at the talks, nor was the renewal of the START Treaty, an agreement to limit strategic missiles that expires in 2009.

While the Moscow meeting yielded no progress, Secretary Gates says, if both sides succeed in working together, it would mark a major strategic shift in relations.

The talks came ahead of President Putin's visit next week to Iran to attend the Caspian Sea Summit. Referring to Iran's nuclear program, Secretary Rice reiterated the U.S. position that Washington will reverse 28 years of American policy and discuss anything Iran wishes to discuss, if Tehran suspends its nuclear enrichment.

Another so-called Two Plus Two meeting of the foreign and defense ministers of both countries is to be held in the United States in six months. In the meantime, U.S. and Russian experts will seek to narrow differences.