U.S. stock index futures were largely flat Wednesday as investors evaluated President Donald Trump's latest tariff threats and awaited minutes of the Federal Reserve's January meeting, expected later in the day.

The U.S. president said on Tuesday that he intends to impose auto tariffs "in the neighborhood of 25%" and similar duties on semiconductor and pharmaceutical imports.

Minutes of the U.S. central bank's January policy meeting - where voting members elected to let interest rates stand and Fed Chair Jerome Powell said there would be no rush to cut them again until inflation and jobs data made it appropriate - are scheduled to be released at 2 p.m. ET.

Investors will look for clues on the Fed's rate path in the minutes, in light of mixed consumer and producer prices data last week along with a sharp drop in retail sales, which had sent Treasury yields lower.

"Keep an eye out for further discussions on the impact of Trump's policies and possible insights into how members have changed their views on the timing of further rate cuts, if any, compared to the December forecasts," Karl Steiner, head of analysis at SEB, said in a note.

Traders currently see at least one 25-basis-point rate cut and a more than 43% chance of an additional lowering by December, according to LSEG data.

Since his inauguration four weeks ago, Trump has imposed a 10% tariff on all imports from China, on top of existing levies. He also announced and delayed for a month 25% tariffs on goods from Mexico and non-energy imports from Canada.

The S&P 500 eked out an all-time closing high in the last session, lifting tech heavyweights Microsoft and Nvidia.

At 04:53 a.m. ET, Dow E-minis were up 36 points, or 0.08%, S&P 500 E-minis were up 3.5 points, or 0.06%, and Nasdaq 100 E-minis were up 17 points, or 0.08%.

Retail giant Walmart's results, a bellwether for how the American consumer is faring, are due later this week.

Earnings from contract research firm Charles River Laboratories and chipmaker Analog Devices are on the radar before the bell.

Arista Networks dropped 3.8% despite the cloud computing provider forecasting first-quarter revenue above Wall Street estimates.

Bumble slid 15.7% after the dating app operator forecast first-quarter revenue below analysts' estimates.

Celanese lost 13.1% after the specialty chemicals company reported a quarterly loss.