LEADERS OF SEVERAL EX-SOVIET NATIONS MET FRIDAY TO DISCUSS PLANS TO STRENGTHEN THEIR ECONOMIC ALLIANCE AND BOLSTER DEFENSE AND SECURITY COOPERATION, ACCORDING TO AP. LEADERS OF RUSSIA, BELARUS AND FOUR CENTRAL ASIAN NATIONS _ UZBEKISTAN, KAZAKHSTAN, KYRGYZSTAN AND TAJIKISTAN _ SAT DOWN FOR A SUMMIT OF THEIR EURASIAN ECONOMIC COMMUNITY IN THE BELARUSIAN CAPITAL, FOCUSING ON PLANS TO FORM A CUSTOMS UNION. OPENING THE TALKS, BELARUS' AUTHORITARIAN PRESIDENT ALEXANDER LUKASHENKO ALSO SAID THEY WILL DISCUSS WAYS TO COORDINATE STRATEGIES FOR JOINING THE WORLD TRADE ORGANIZATION. LATER IN THE DAY, THE SAME SIX LEADERS AND THE PRESIDENT OF ARMENIA WILL TAKE PART IN A SUMMIT OF THE COLLECTIVE SECURITY TREATY ORGANIZATION. BELARUS THIS WEEK IS HOSTING THE LARGEST EVER JOINT MILITARY MANEUVERS WITH RUSSIA, ENVISAGING A JOINT RESPONSE TO AN UNNAMED, OUTSIDE MILITARY THREAT. BELARUSIAN OFFICIALS SAID EARLIER THIS WEEK THAT RUSSIAN PRESIDENT VLADIMIR PUTIN AND OTHER HEADS OF STATES WERE TO WATCH THE EXERCISE OVER THE WEEKEND, BUT THE KREMLIN SAID FRIDAY THAT PUTIN WOULDN'T ATTEND IT.