Russia's Defence Minister Sergei Ivanov has spoken out in favour of creating a joint air defence system of the CIS countries. At the same time, the head of the Russian Defence Ministry noted that "military cooperation is multi-level and multi-speed in nature." Ivanov said this addressing the members of the Federation Council (Upper Chamber of the Russian Parliament) on Wednesday. The Minister recalled that such cooperation has been maintained within the framework of the Collective Security Treaty and includes joint air defence exercises. In particular, the Belarussian military hold regular exercises at Russian testing grounds. As for the other CIS states, joint projects "may be implemented in case of a mutual desire of the sides," stressed the Russian minister.