Wall Street ends mixed as traders watch US-China talks

The S&P 500 has ended slightly higher, lifted by Amazon and Alphabet, while investors watched US-China negotiations aimed at mending a trade dispute that has rattled financial markets for much of the year.

Top officials from both countries have kicked off discussions, looking to get back on track with a preliminary trade agreement struck last month that had briefly cooled tensions between the governments of the world's largest economies.

"The market deems any dialogue with Beijing as progress, whether or not it leads to tangible results. The market is just going to take the administration's word for it, until proven otherwise," said Jake Dollarhide, CEO of Longbow Asset Management in Tulsa, Oklahoma.

Amazon and Google parent Alphabet each gained more than 1.0 per cent and helped keep the S&P 500 in positive territory.

Amazon.com said it plans to invest at least $US20 billion ($A31 billion) in Pennsylvania to expand data centre infrastructure, adding to the billions of dollars the technology giant has committed to the expansion of artificial intelligence.

Apple dipped 1.2 per cent after the iPhone maker kicked off its annual software developer conference with incremental developments that did little to impress investors.

The S&P 500 climbed 0.09 per cent to end the session at 6,005.88 points, the Nasdaq gained 0.31 per cent to 19,591.24 points and the Dow Jones Industrial Average ended essentially unchanged at 42,761.76 points.

Of the 11 S&P 500 sector indexes, six declined, led lower by utilities, down 0.66 per cent, followed by a 0.55 per cent loss in financials.

Expectations of more trade deals between the US and its major trading partners, along with upbeat earnings and tame inflation data, helped US equities rally in May, with the S&P 500 and the tech-heavy Nasdaq notching their best monthly gains since November 2023.

The S&P 500 remained about 2.0 per cent below its all-time high touched in February while the Nasdaq is about 3.0 per cent below its December record high.

Warner Bros Discovery fell about 3.0 per cent after the company said it would separate its studios and streaming business from its struggling cable television networks.

Immediately after the announcement, it had surged as much as 13 per cent.

Shares of McDonald's dipped 0.8 per cent after Morgan Stanley downgraded the fast-food restaurant to "equal-weight" from "overweight".

Robinhood Markets dropped almost 2.0 per cent after S&P Dow Jones Indices left S&P 500 constituents unchanged in its latest rebalancing, following recent speculation that the online brokerage would be added to the benchmark index.

Major data releases this week include readings on May consumer prices on Wednesday and initial jobless claims on Thursday.

While investors widely expect the Federal Reserve to keep interest rates unchanged next week, focus will be on any signs of pick-up in inflation as Trump's tariffs risk raising price pressures.

Advancing issues outnumbered falling ones within the S&P 500 by a 1.1-to-one ratio.

The S&P 500 posted 16 new highs and 4 new lows; the Nasdaq recorded 97 new highs and 46 new lows.

Volume on US exchanges was relatively light, with 17.1 billion shares traded, compared to an average of 17.8 billion shares over the previous 20 sessions.