When NATO leaders meet in Romania today to decide whether to put U.S. allies Georgia and Ukraine on a path toward eventual membership, they will find themselves wedged between Washington's firm backing of the former Soviet states' bids and a Kremlin digging in its heels against any further eastward expansion by the alliance.

The Bush administration has been pushing hard for the 26-nation alliance to grant the two countries Membership Action Plan status, a step toward qualifying for inclusion in NATO.

Appearing alongside President Viktor Yushchenko in Kiev on Tuesday, President Bush expressed strong support for Ukraine's membership ambition -- a stand that risks a diplomatic confrontation with Russia even as the administration sought a deal with President Vladimir Putin over U.S. missile defenses in Europe.

Bush rejected Russian suggestions that he soft-pedal the issue in exchange for a deal on missile defense or Afghanistan. "There's no tradeoffs. Period. And I told that to President [Vladimir] Putin."

That support for NATO enlargement faces resistance from the Kremlin, which in recent years has amassed the energy wealth and political muscle it needs to influence Western European NATO nations economically tied to Russia. In the past decade, it has watched with increasing irritation as a Western alliance formed to oppose it during the Cold War has approved expansion into 10 countries once within the Soviet fold.

MISSILE DEFENSE PLAN

Scrambling to seal a missile defense deal this weekend, the United States is offering guarantees to assure Russia that the system isn't a European military threat aimed at them. Among them: The U.S. won't activate new sites in Poland and the Czech Republic unless Iran proves itself an imminent threat to Europe by test-flying a missile capable of reaching the continent.

A broader but less-specific "strategic framework" seems assured when Bush sits down with Putin on Sunday in the Black Sea resort of Sochi. But the White House seems to think there could be a bigger breakthrough on the defense system. Defense Secretary Robert Gates said in Copenhagen on Tuesday that he saw reason for optimism but was not ready to predict the Russians would decide the time is right for a deal.

TODAY'S SUMMIT EVENTS

The summit kicks off with a working dinner in Bucharest, Romania, for NATO heads of state. The agenda is expected to focus on NATO operations, enlargement and the development of partnerships. Talks continue through Friday.

KEY ISSUES ON THE AGENDA

Afghanistan: The summit will adopt a "vision statement" stressing NATO's long-term commitment, but urge greater efforts to train the Afghan army to eventually take over. On Tuesday, French Prime Minister Francois Fillon said it may contribute "several hundred" more troops. It was the first time a senior French official publicly gave a figure for France's plans.

Balkan expansion: NATO is to invite Croatia and Albania to join. Greece will veto Macedonia's bid to join unless there is a last-minute deal to change the candidate country's name.

New threats: It will endorse plans to step up cooperation against cyber-attacks through an Estonia-based center.

NEWS SERVICES