A top European official has backed a multi-trillion-euro "Marshall"-style plan to rebuild Ukraine, pledging the firepower of the European Union's lending arm for what he said must be a global rescue effort.

Werner Hoyer, president of the European Investment Bank, told Reuters that Europe must not be left alone to foot the vast bill that he predicted could run into the trillions.

Hoyer told Reuters that the cost of rebuilding Ukraine had been discussed at recent meetings at the United Nations, the International Monetary Fund and World Bank in Washington.

"What will it cost to rebuild, reconstruct Ukraine? Figures were flying around the room ... but one thing is quite clear to me: We are not talking about millions but trillions."

Under the post-World War Two U.S. scheme known as the Marshall Plan, the United States granted Europe the present-day equivalent of some $200 billion over four years in economic and technical assistance.

"The international community must provide huge amounts of support," Hoyer said.

(Reporting By Marc Jones; editing by John O'Donnell and Hugh Lawson)