The U.S. said it will begin imposing 25 percent duties on an additional $16 billion in Chinese imports in two weeks, escalating a trade war between the world's two biggest economies.

Customs will begin collecting duties on 279 product lines, down from 284 items on the initial list, as of Aug. 23, the U.S. Trade Representative's Office said in an emailed statement Tuesday. The new list covers products ranging from motorcycles to steam turbines and railway cars.

It will be the second time the U.S. slaps duties on Chinese goods in about the past month, despite complaints by American companies that such moves will raise business costs and eventually consumer prices. The U.S. levied 25 percent duties on $34 billion in Chinese goods July 6, prompting swift in-kind retaliation from Beijing. China has vowed to strike back again, dollar-for-dollar, on the $16 billion tranche.