In an interview on CNBC, Fischer said the economic policies following World War II were beneficial to the global economy, notably for China's development, but also for the United States, which was able to buy goods that were not accessible previously.

"I'd be concerned if that basic model is overturned," he said. "On average, the way to grow was to integrate the world economy and that worked spectacularly for China."

The Trump administration's "America first" focus has tilted toward protectionism to reduce the large US trade deficit, including threatening tariffs on imports from trading partners like Mexico and China.

On monetary policy, Fischer confirmed that he is expecting to see two more interest rate hikes this year, in line with the forecast of most Fed policymakers.

"That seems to be about right. That's my forecast as well," he said.

The Fed has raised the benchmark lending rate twice in the last four months as job creation has remained solid, bringing down interest rates, and inflation has begun to creep up.

He also said the US central bank was closely monitoring the Trump administration's promised fiscal stimulus plans, and had included a small fiscal expansion in its forecast.

While his term as vice chair comes to an end in June 2018, Fischer can remain at the Fed as a governor through January 2020, but he said he had not yet decided whether or not to remain beyond next year.