US stocks extended losses in late morning trade on Tuesday, weighed down by technology and industrial stocks, amid disappointing earnings and weak consumer confidence data.

The selling comes a day after Wall Street suffered its worst day of 2017, as investors turned wary about the consequences of President Donald Trump's isolationist policies such as curbing travel to the United States.

The S&P; 500 technology sector led Tuesday's decline, down 0.9 per cent. Microsoft and Apple were the biggest drags.

"Many technology CEOs have come out publicly against Trump's immigration policies and it certainly hurts the sector's access to highly qualified labour," said Brant Houston, portfolio manager at Atlantic Trust in Denver, Colorado.

Apple is scheduled to report after markets close on Tuesday.

A clutch of disappointing quarterly earnings across sectors added to the dour mood.

Package delivery company UPS dropped 6.2 per cent to $US109.71 after posting a quarterly loss and issuing a full-year profit forecast that missed expectations. The stock weighed the most on the S&P; industrials sector.

Under Armour was the biggest percentage loser on the index; its Class A shares shed 25 per cent. The sportswear maker's gloomy sales and forecast also dragged down bigger rival and Dow component Nike 1.3 per cent.

A report from the Conference Board showed the consumer confidence index fell by a bigger-than-expected margin in January after hitting a 15-year high the previous month.

The healthcare sector rose 0.6 per cent after Trump called for easing regulations for drug makers, lowering taxes and prices of medicines.

At about 11.30am in New York, the Dow is down 0.8 per cent, the S&P; 500 is 0.5 per cent lower and the Nasdaq has shed 0.6 per cent.

The Dow's worst performers were Goldman, Caterpillar, JPMorgan and Nike. Twenty-six of the Dow's 30 components were lower.

The US dollar slumped 0.9 per cent against a basket of six major currencies and was on track its worst month since March 2016. Trump's top trade adviser Peter Navarro accused Germany of using a "grossly undervalued" euro to gain a competitive advantage.

Safe-haven gold rose 1.6 per cent, the precious metal's biggest one-day percentage gain since September.

A two-day meeting of the Federal Reserve's policy-setting is also on investors' radar. The central bank is not expected to raise rates, after a move in December, but investors will focus on how policymakers view the economy under a Trump presidency. Policymakers will release a statement on Thursday morning AEDT.