Leaders of 26 members states of Nato, who descended on Bucharest for the alliance's three-day summit on April 2, have agreed to extend invitations to join the organisation to Albania and Croatia, but were yet to reach agreement on Macedonia's application.

Talks on the issue would continue on April 3, Nato spokesperson James Appathurai told reporters at a media briefing.

Greece has threatened to veto Macedonia's bid over the name dispute with Skopje. Greece refuses to accept its neighbour's constitutional name, saying Macedonia is the name of Northern Greece and that having Skopje use it is indicative of its implicit territorial claims over the northern Greek province. The alliance uses the consensus principle, meaning that no decision can be made unless all member states are in agreement.

"The invitation will be postponed," one European Nato diplomat told Reuters.

Doing so would fuel radical feelings in the country and destabilise the region, Albania's prime minister Sali Berisha said. "The stability of this neighbor is very crucial for Albania, for Kosovo, for Greece, to Bulgaria, to all its neighbors. My fear is that radicals from all ethnicities there could be strengthened," he told Reuters.

A possible solution would be to extend a conditional invitation, pending the resolution of talks between Skopje and Athens, a British source familiar with the talks told Romanian-language news agency Newsin.

Georgia and Ukraine, two more countries hoping to secure membership action plans, the first step towards Nato membership, were unlikely to be successful, Reuters said.

Germany remains opposed to offer such roadmaps to the two former Soviet republics, considering them unprepared, despite strong lobbying from the US. Russia is also strongly against what it sees as an encroachment of its traditional sphere of influence.