RIGA -- U.S. President George Bush said on Friday enlarging NATO would help the fight against terror, boosting the confidence of ex-communist states across Eastern Europe that they will soon be invited into the alliance.

Speaking in a videotaped message Bush reaffirmed his administration's strong support for a bigger NATO, saying alliance expansion was integral to Washington's desire to see the defense bloc evolve to tackle a new range of threats.

"We seek a new Europe that has buried its historic tensions and is prepared to meet global challenges beyond Europe's borders," he told heads of government of states hoping to get a membership invitation at NATO's Prague summit in November. "NATO must prepare itself to fight and defeat terror," said Bush, "and new members will help improve NATO's capabilities."

The message was another strong signal that NATO leaders will invite in as many as seven former Warsaw Pact nations, joining Poland, Hungary and Czech Republic, who entered in 1999.

Baltic states, Latvia, Lithuania and Estonia, ex-Yugoslav republic Slovenia, and former laggards Romania and Bulgaria now look safe bets as Bush pursues his vision of the U.S.-dominated alliance growing "from the Baltic to the Black Sea".

Slovakia will also join, provided its people do not vote autocratic ex-premier Vladimir Meciar or his HZDS party back into power in a September election. Meciar is deemed not to meet the standards of democratic behavior needed to join NATO.

British Prime Minister Tony Blair joined Bush in sending a taped message backing "enlargement on as broad a basis as possible," to help defeat September 11-style terror attacks.

"These are probably the most encouraging speeches from two of the most important leaders of the alliance that we have had so far," said Romanian Foreign Minister Mircea Geoana.

---------- No Names Yet ---------- Bush did not name any countries he wanted to see in NATO to ensure candidates remain under pressure to pursue economic, military and political changes.

Candidates can still "self-disqualify" at the last minute, officials warn, by democratic missteps and fluffing reform.

Bulgaria and Romania, once given only an outside chance, appear to have earned their place by portraying themselves as an anchor of stability on Europe's southeastern flank. "We feel we are at the threshold," said Bulgarian Foreign Minister Solomon Passy, "but we still have to open the door."

The Balkan pair have rushed to assist Washington by sending troops to Afghanistan, opening their air space and allowing U.S. warplanes to refuel at military airbases.

To the delight of East Europeans hoping foreign investment will flow in following NATO entry, a "robust" enlargement has become a key part of Washington's strategy of reshaping NATO to help defeat what Bush called "the forces of chaos and hatred".

A new relationship with eastern states like Russia, with which NATO has forged a new strategic partnership, and a drive to improve the ability of NATO's European armies to fight outside their backyards, are the other part of Bush's plan.

"New capabilities, new members and a new relationship with the East -- we think if we can achieve all this by Prague then the alliance is going to be stronger," said Nicholas Burns, U.S. ambassador to NATO.

Even after the Prague meeting the new NATO nominees will be on a knife-edge as they watch the crucial U.S. ratification process unfold. Officials say the mood on Capitol Hill is positive but Senate approval cannot be taken for granted.

Parliamentary approval of new members by the legislatures of the 19 current NATO states will likely take until mid-2004.