Bulgaria on Thursday joined the NATO Rapid Deployable Corps Headquarters in Thessaloniki in northern Greece, according to a memorandum signed by country\'s Chief of Defense General Simeon Simeonov and his Greek counterpart, General Mikhail Kostarakos. \"This memorandum will help to lift Bulgaria\'s contribution to NATO, and implement the initiative for linking the forces in the best possible way in terms of the continuing economic crisis,\" Simeonov said at the signing ceremony. Joining the Corps would help maintain the required operational capabilities for participation in NATO operations, with a focus on joint training and exercises in peacetime, Simeonov said. Kostarakos said signing of the memorandum was a significant event, which added new dynamism to the bilateral military relations. Bulgaria, a NATO member since 2004, has been participating in several key missions of the alliance such as the International Security Assistance Force (ISAF) in Afghanistan.