NEW YORK (AFP) - Wall Street stocks finished slightly lower on Friday (July 20) as President Donald Trump's latest tariff threats and attack on the Federal Reserve kept a lid on gains despite largely solid earnings.

The Dow Jones Industrial Average finished down less than 0.1 per cent at 25,058.06.

The broad-based S&P 500 dropped 0.1 per cent to close the week at 2,801.83, while the tech-rich Nasdaq Composite Index also fell 0.1 per cent to 7,820.20.

With the majority of larger earnings reports still to come, companies are on track to report second-quarter earnings about 20 per cent above those of the year-ago period, according to a note from Credit Suisse.

"Overall, the earnings season has been strong, topline revenue growth has been solid as well," said Quincy Krosby, chief market strategist at Prudential Financial.

But Trump kept some of the focus on trade fights after telling CNBC in an interview that he was willing to significantly expand the conflict with China by adding tariffs to all US imports.

On Twitter, Trump also accused China and the European Union of manipulating their currencies to promote their exports at the expense of the US, and criticized the Fed for raising interest rates.

Among companies reporting results, Microsoft won 1.8 per cent after reporting a 10 per cent rise in quarterly profit to US$8.8 billion (S$12 billion) behind strong revenue gains in Internet search ads, gaming, Windows and other key businesses.

Honeywell International advanced 3.8 per cent as the industrial company raised its forecast for annual profits and sales amid strong demand from aerospace and defense clients.

But General Electric sank 4.5 per cent after it reported a 29.7 per cent drop in second-quarter earnings to US$615 million on continued power industry weakness.