President Bush will meet the countries' foreign ministers

The United States Senate has voted unanimously to allow seven former communist Eastern European nations to join the Nato military alliance.

Senators backed permitting Bulgaria, Estonia, Latvia, Lithuania, Romania, Slovakia and Slovenia to join by 96 votes to zero.

The new members will increase Nato's forces by about 200,000 troops and add new bases that could be used for missions worldwide.

Foreign ministers of the seven nations were in the Senate gallery to witness the vote and will later meet President George W Bush.

"This is historic for these seven countries, vital in continuing to strengthen the North Atlantic alliance and central to US security and relationships in the world," said Richard Lugar, chairman of the Foreign Relations Committee.

They have acted as better allies than some of the members that are currently in Nato Senator George Voinovich

Senate Democratic Leader Tom Daschle described the expansion of Nato as another step toward "the creation of a Europe that is whole, that is free".

"This is the beginning of a partnership that will produce greater world stability, greater international involvement in world affairs and a partnership with countries that will increasingly become valuable partners and allies of the United States," he added.

All 19 Nato member states have to approve the expansion, and 16 of them have yet to ratify the expansion.

In the US, no House of Representatives vote is needed on the expansion.

Difficult time

Of the seven candidate nations, only Slovenia was not part of the US-led coalition that went to war against Saddam Hussein's Iraq.

"These countries already make significant contributions that strengthen the transatlantic relationship," said Senator George Voinovich.

"They have acted as de facto allies. In fact, they have acted as better allies than some of the members that are currently in Nato."

The ratification vote comes at a difficult time for Nato following a dispute over war with Iraq.

In February, Belgium, France and Germany blocked a request by Turkey for help in strengthening its defences ahead of the war with Iraq.

They said such assistance could undermine hopes of avoiding a war.