NEW : President Erdogan says deal possible on nuclear technology swap with Iran . Russian President Medvedev says talks are ` ` last chance '' to resolve nuclear issue . U.N. Security Council decision imminent on possible sanctions against Ms . Lula in Iran ahead of summit of 15 nuclear nations meeting in Tehran .
NEW : Tayyip Erdogan says deal possible on nuclear fuel swap with Iran . Russian President Medvedev says talks are `` last chance '' to resolve nuclear issue . U.N. Security Council decision imminent on possible sanctions against Iran . Lula in Iran ahead of Group of 15 developing nations meeting in Tehran .