CAMBRIDGE, MASS., JUNE 7 -- West German Chancellor Helmut Kohl, addressing graduates at Harvard University, sketched a vision today of a unified Germany in a free and peaceful "United States of Europe" and open to all who wish to join.

Kohl, a forceful proponent of speedy reunification of East and West Germany, predicted that a new union of European nations would be forged by the end of the decade.

"I am firmly determined that this federation should not be an exclusive club confined to the present members of the European Community," he said. "It must not exclude the Poles, Czechs and Slovaks or Hungarians or any other Europeans who want to join this federation."

Kohl used the occasion of Harvard's 339th commencement to thank Americans for their help in rebuilding Western Europe, noting that then-Secretary of State George C. Marshall had spelled out his postwar recovery plan on the same platform 43 years ago.

Kohl also urged increased U.S. participation in European affairs and business, particularly in helping to rebuild the stalled economies of Eastern Europe.

Kohl did not mention the Soviet Union and gave no indication of the role Moscow would play in Europe's future. He dwelt instead on broader themes of liberty, prosperity and human rights across Europe. He was applauded repeatedly when he expressed support for respecting the "diversity" of ethnic, cultural and religious minorities.

"We Germans do not want to couple the unity of our fatherland with the displacement of existing borders," Kohl said, repeating his pledge that the German-Polish border "remains inviolable."

Kohl and President Bush have scheduled a dinner meeting today at the White House. Kohl praised the Bush administration for its "exemplary foresight" in European affairs and said that "close cooperation and friendship with President Bush mean a great deal to me."