NEW YORK: The S&P 500 was little changed on Tuesday following a three-day rally as a drop in Apple shares overshadowed optimism from remarks made by US and China officials in pledging firm commitment to a Phase One trade deal.

The benchmark S&P 500 opened at a record high as the news eased some concerns the deal could be on shaky ground. Investors also anticipate the centerpiece event of the week - an annual conference of US central bankers where Federal Reserve Chairman Jerome Powell is scheduled to speak.

The S&P 500 and Nasdaq logged new closing highs on Monday, boosted by signs of progress in developing treatments and vaccines for Covid-19.

Among stocks, Salesforce.com Inc, Amgen Inc and Honeywell International Inc climbed between 3.6% and 4.6% on news they would join the blue-chip Dow Jones Industrial Average index on Aug. 31.

Cloud computing heavyweight Salesforce.com is expected to report second-quarter results after markets close.

The three companies will replace Exxon Mobil Corp, Pfizer Inc and Raytheon Technologies Corp, which were down between 1.9% and 3%.

Apple Inc's 1.2% drop weighed heavily on the three main indexes and the shares were on course to end five days of gains.

At 11:08 a.m. ET, the Dow Jones Industrial Average was down 122.19 points, or 0.43%, at 28,186.27, the S&P 500 was up 0.50 points, or 0.01%, at 3,431.78. The Nasdaq Composite was up 24.31 points, or 0.21%, at 11,404.03.