The signing, conducted at a ceremony at alliance headquarters in Brussels, was largely a formality after NATO leaders agreed to usher the two Balkans countries into the 26-member organization at a summit in Bucharest in April. However a third NATO aspirant, Macedonia, was absent from the ceremony after its accession goal was blocked by Greece in a long-running dispute over its name.

Diplomats say that even if the name dispute can be resolved soon, it will be hard for Macedonia to complete procedures needed to join NATO alongside Albania and Croatia, who are expected to enter the alliance at a summit in April 2009. (Reuters)