WASHINGTON, April 23 (Reuters) - The European Union must keep the door to joining the group open to potential new members such as the Balkan countries, World Bank President Robert Zoellick said on Thursday.
He also said Europe must use the current global economic crisis as an opportunity for further integration, including consolidating the number of seats the bloc has at the G20.
Zoellick said Serbia was a good example of a country that needed the prospect of European Union membership.
"The way they can keep on a peaceful and constructive course is to say there is a pathway to Europe," he said.
Ukraine could also benefit from the prospect of closer ties to Europe, he said.
It would be a mistake to let Europe's integration progress of the last 20 years "unravel," he said.
Asked about Europe's representation at the G20, he said: "At some point if integration were to mean something it would be nice if there was a smaller number of European countries." (Reporting by Anna Willard and Jan Strupczewski; Editing by Padraic Cassidy)