Belarus has refused to sign on to Russia's plan to form a NATO-style rapid reaction force that would respond to such disasters as terrorism.
Belarus boycotted Sunday's summit of the Russian-led Collective Security Treaty Organization to protest a Russian ban on Belarusian dairy products. Russia banned Belarusian milk and other dairy products earlier this month apparently for health reasons.
Belarusian President Alexander Lukashenko accused Russia of trying to force his country to its knees. The nation called any decisions made at Sunday's summit illegal because not all CSTO members were there.
Russian President Dmitri Medvedev said he hopes Belarus gets over what he calls "milk hysterics" and joins the effort to improve regional security.
Uzbekistan also did not sign the deal for a rapid reaction force Sunday, apparently because of misgivings about Russian control.
Seven former Soviet states make up the CSTO - Armenia, Belarus, Kazakhstan, Kyrgyzstan, Russia, Tajikistan and Uzbekistan.
Russia and Belarus traditionally have been close allies. But Belarus recently accused Russia of trying to get back at it by denying loan payments because of Belarusian efforts to seek better ties with the West.
Belarus also has failed to follow Russia in recognizing independence for two breakaway Georgian regions, Abkhazia and South Ossetia.
Some information for this report was provided by AFP and AP.