NEW YORK (AFP) - Wall Street stocks ended near flat on Wednesday (Aug 8) as the United States and China continued to spar over trade policy and as Tesla pulled back following a surprise go-private proposal from its chief.

The Dow Jones Industrial Average dropped 0.2 per cent to 25,583.75.

The broad-based S&P 500 slipped less than 0.1 per cent to 2,857.70, while the tech-rich Nasdaq Composite Index added 0.1 per cent at 7,888.33.

China said it would impose 25 per cent tariffs on a further US$16 billion (S$21 billion) of US goods starting on Aug 23, making good on its promise to retaliate against new American levies announced late Tuesday on US$16 billion in goods set to take effect the same day.

Analysts said markets were also consolidating recent gains and that trading volumes were low, with many traders on holiday.

"The market is looking for direction after earnings season," said Adam Sarhan of 50 Park Investments. "It's normal to see a pause."

One day after chief executive Elon Musk stirred investors with a surprise proposal to take Tesla Motors private, shares of the electric automaker fell 2.4 per cent as some analysts expressed scepticism.

Snapchat parent Snap was another weak stock, falling 6.7 per cent after the company reported a drop in daily active users.

Among other companies reporting earnings, Dow member Disney fell 2.2 per cent, while CVS Health gained 4.1 per cent.

Leading petroleum producers such as ExxonMobil and Chevron fell on a pullback in oil prices.