U.S. Secretary of State Condoleezza Rice said Thursday U.S.-Russia relations are good on many things but are "difficult" in some areas.

"On many things we have done very well, but the fact is that on some others it's been a difficult period," Rice said while testifying at a Senate committee.

"The Russians, I think, do not accept fully that our relations with countries that are their neighbors, that were once part of the Soviet Union, are quite honestly good relations between independent states and the United States," Rice said.

"It's even more difficult when one looks at what is happening domestically in Russia where I think it's fair to say that there has been a turning back of some of the reforms that led to the decentralization of power out of the Kremlin," Rice said.

Rice made the comments before her planned visit to Moscow next week to persuade Russia to accept a U.S. plan to deploy missile defense system in East Europe.

The United States has claimed the missile defense system is aimed against states and groups in the Middle East that are seeking weapons of mass destruction, not against Russia. Russia has strongly opposed to the plan and said the missile system poses a threat to its security.

U.S.-Russia relations have been cool in recent years due to deep differences between each other on many issues.