FILE PHOTO: U.S. President Donald Trump holds a news conference in the White House East Room in Washington, U.S. March 6, 2018. REUTERS/Leah Millis

WASHINGTON (Reuters) - U.S. President Donald Trump said on Wednesday that China has been asked to develop a plan to reduce its trade surplus with the United States, without giving any details on how such a request had been conveyed.

Trump is pressing to implement campaign promises of hardening the U.S. stance on trade. Last week, he announced that he planned to impose heavy tariffs on imported steel and aluminum. While that has been greeted by worries at home and abroad that it could spark a global trade war, some critics also said the planned move did not focus enough on China.

“China has been asked to develop a plan for the year of a One Billion Dollar reduction in their massive Trade Deficit with the United States,” Trump wrote in a post on Twitter, mistakenly referring to a deficit where Beijing runs a surplus.

“We look forward to seeing what ideas they come back with,” Trump wrote.

It was not clear who had asked Beijing for this plan, and the White House did not immediately respond to a request for details.

China ran a record goods trade surplus with the United States last year of $375.2 billion.

(This story corrects final paragraph to show the trade surplus figure is for goods trade, not goods and services)