Britain has been an EU member that has not used the single currency, but it has prospered well. The EU now is like putting together patches of people, not a true federation," he said.
He expected Brexit to encourage other EU members to consider leaving, particularly Greece and the Baltic states.
He also expected greater ease for Asean in striking a free-trade agreement with the UK. A deal with the EU is complex, given the bloc's reluctance to reduce its huge agricultural subsidies, he said.