He noted that China's powerful expansion over the past three decades was deeply founded on abundant cheap labor, massive investment and a focus on the export industry.
"This is no longer a viable model of growth for China, or for the world economy," he said.
He acknowledged though that Beijing has focused its economic reform program on making growth more sustainable by strengthening domestic household consumption and placing a lower emphasis on exports, and also boosting the services sector.
As for Europe, Sheets said, "the recovery remains fragile and uneven with weak demand, and some countries are still overly dependent on exports for growth."
"It is critical that countries with large external surpluses and fiscal space pursue demand-boosting policies, such as investment in infrastructure," he said.
Copyright Agence France-Presse, 2014