"We believe strongly in NATO's open-door policy," Rice told a news conference Monday after meeting with British Foreign Secretary David Miliband.

On the agenda of Tuesday's NATO's foreign ministers' meeting in Brussels is the question of membership plans for ex-Soviet states Georgia and Ukraine, which Russia strongly opposes and France and Germany see as ill-timed.

The United States has abandoned a formal roadmap as a way for both nations to enter NATO but Rice repeated strong U.S. support for a decision made at a NATO summit in Bucharest last April for Georgia and Ukraine to one day become members.

She said NATO's Ukraine and Georgia commissions could be a used to help prepare them for membership, bypassing the formal roadmap route.

"I think you can talk about tactical differences among the allies but no one wants to see a circumstance in which Ukraine and Georgia are shut out," Rice said.

Rice also cautioned NATO members on Monday against military activities with Russia but said she did not oppose contacts via the NATO-Russia Council.

Ties with Russia will also be discussed by the NATO foreign ministers. She urged members to be cautious while Moscow still had troops in Georgia's breakaway regions of South Ossetia and Abkhazia.

NATO canceled military exercises with Russia after the brief war in August between Moscow and Georgia and Rice made clear she did not think these should be resumed.

"There are certain sorts of activities like military-to-military contacts that seem to me to be problematic when the Russian military is sitting in Georgian territory or the separatist states," she told reporters

At the Brussels talks, foreign ministers will also review a decision to suspend high-level meetings on the main NATO-Russia dialogue forum, the NATO-Russia Council, following the conflict with Georgia.

Rice said she was not opposed "in principle" to contacts with Russia via the council.

"I have no problems with the NATO-Russia Council activities but we should be very attentive to what the Russians are doing and are they are living up to their obligations," she said.

"I do not want to make a general rule here," she added.

She said Russia's "ill-tempered" decision to invade Georgia last August turned out badly and Moscow failed to bring down the Georgian government even though Russian Foreign Minister Sergei Lavrov told her that was an aim.

At the height of the Georgia-Russia crisis, the United States spearheaded international isolation of Russia but Rice appeared to take a more conciliatory line on Monday.

"This is not actually a new Cold War," she said.

While Washington opposed Russia's behavior over Georgia, she said it had worked closely with Moscow on issues from North Korea and Iran's nuclear programs to the Middle East.

(Additional reporting by Adrian Croft; Editing by Charles Dick)