A prominent economist has predicted the United States won't follow through on President Donald Trump's strong rhetoric and label China as a currency manipulator.

Yu Yongding, a former member of the Chinese Central Bank's monetary policy committee, said such a "stupid" action would go against Washington's own interests.

He said the renminbi would depreciate if China stops its "intervention" and the result would be bad for the US.

If the value of the renminbi falls, it will boost China's exports, which may lead to a widening of Washington's trade deficit with Beijing.

Trump declared China "grand champions" of currency manipulation late last month. He had pledged to declare China a currency manipulator on his first day in the White House, but he has not carried out the threat.

"It would be really good if he did," Yu joked. "But he didn't, showing people in the US government have told him that doing so would be stupid."

He said he believed that the US Treasury Department would not announce China as a currency manipulator in its April report.