Wall Street indexes closed higher on Wednesday, led by the tech-heavy Nasdaq as Nvidia briefly reached a US$4 trillion valuation, and Federal Reserve meeting minutes fuelled hopes that inflation pressures from US President Donald Trump's tariffs would not derail interest rate cuts this year.

The minutes for the mid-June meeting showed that most Fed officials said they expect rate cuts will be appropriate later this year, with price shocks from Trump's import taxes expected to be "temporary or modest." However, there was little support for a rate cut at the end of July meeting.

Nvidia became the world's first company to hit a US$4 trillion market value on Wednesday morning, solidifying its position as one of Wall Street's most favoured stocks to tap in the ongoing surge in demand for artificial intelligence technologies.

Shares in the chip company ended Wednesday up 1.8 percent with a market capitalisation of around US$3.97 trillion.

It helped lift the Nasdaq, which closed at an all-time high.

Besides Nvidia, other market boosts came from megacap companies including Microsoft Corp, which rose 1.4 percent and Amazon.com, which added 1.5 percent.

Trump issued letters to seven countries on Wednesday, calling for tariffs of 30 percent on Algeria, Iraq, Libya and Sri Lanka, 25 percent on Brunei and Moldova, and 20 percent on the Philippines.

The European Union has said it could reach an outline trade agreement with the US in the coming days.

The Dow Jones Industrial Average rose 0.49 percent to 44,458, the S&P 500 gained 0.61 percent to 6,263 and the Nasdaq Composite gained 0.95 percent to 20,611. (Reuters)