Zagreb  - US President George W Bush on Saturday welcomed Croatia's "historic" invitation to join NATO and sought to soothe embittered Macedonia by holding out hope that it would soon follow.

Bush visited Croatia in an additional show of support for a country that fought for its independence last decade and was invited this week to join NATO, along with Albania.

"We look forward to welcome you to as partners in NATO," Bush told a crowd in central Zagreb. "The invitation to Croatia and Albania to join is a vote of confidence that you will continue with reforms."

He also promised Croatia that "from now on, should anyone threaten your people, America and NATO will stand with you and no one will take your freedom away."

Bush said he regrets that Macedonia, locked in dispute over its name with Greece, was not invited to join. "Our position is clear: Macedonia should take its place in NATO as soon as possible," he said.

Macedonians, who worry that their country would disintegrate amid ethnic tensions if left outside NATO's protective umbrella, were bitterly disappointed over the alliance's bowing to a Greek veto threat.

In another show of support, the Macedonian heads of state and government were also invited to meet Bush in Zagreb along with those of Albania.

For Croatia, Bush pledged to work to ease visa rules to allow Croats easier travel to visit relatives in the US. He gave no details.

But he also reached out to Belgrade, which has pulled away from the West over its support of Kosovo, the province with a majority ethnic Albanian population that declared independence from Serbia.

"We hope that soon a free and prosperous Serbia will find its place in the family of Europe and live in peace with its neighbours," he said.

Serbia fought wars in Croatia, Bosnia and Kosovo during the violent disintegration of the communist Yugoslav federation during the 1990s.

Bush opened his speech to a crowd on Zagreb's central St Marko square with "dobro yutro" - good morning in Croatian. Some 3,000 people who attended were cleared by US security services, local reports said.

Croatian Prime Minister Ivo Sanader thanked the US for its "strong support of Croatia, reflected not just in the invitation to join NATO, but also in this visit."

Bush was scheduled to depart Zagreb later Saturday for talks with Russian President Vladimir Putin in the Black Sea resort of Sochi. (dpa)