PALM BEACH, Fla. (REUTERS) - US President-elect Donald Trump plans to make an announcement related to the economy on Wednesday (Dec 28) afternoon, his transition team said, adding it would be a boost to workers but giving no other details.

Mr Trump plans to make the statement between 4pm and 5pm ET (5am to 6am Singapore time), incoming White House spokesman Sean Spicer told reporters on a conference call, adding that the news "should be very positive for American workers".

A wealthy New York businessman, Mr Trump pledged during his White House campaign to do more to protect workers' interests.

Since winning election last month, he has become personally involved in a series of company issues, including intervening to curb the number of jobs being sent to Mexico by United Technologies Corp's Carrier unit.

He has also called on Boeing Co and Lockheed Martin Corp to lower their costs for US military and government projects.

During his campaign, Mr Trump singled out numerous companies for criticism, including Ford Motor Co, Amazon Inc, Apple Inc, H&R Block Inc, Mondelez International Inc and Starbucks Corp.

Mr Trump takes office on Jan 20.