US equity indexes rose amid gains in government bond yields in midday trading on Wednesday ahead of the Trump administration's tariff announcements later this afternoon.

The Nasdaq Composite rose 0.8% to 17,586.9, the S&P 500 climbed 0.5% to 5,659.8, and the Dow Jones Industrial Average traded 0.4% higher at 42,135.1. Consumer discretionary led the gainers while energy and consumer staples were among the decliners intraday.

President Donald Trump will unveil import tariffs on the US' global trading partners at 4 pm ET in the White House. In a Truth Social post, the president urged Mitch McConnell and three other Republican senators to defeat a bill aimed at undoing the import levies that the president has imposed on Canada.

"Mitch McConnell of Kentucky, Susan Collins of Maine, Lisa Murkowski of Alaska, and Rand Paul, also of Kentucky, will hopefully get on the Republican bandwagon, for a change, and fight the Democrats wild and flagrant push to not penalize Canada for the sale, into our Country, of large amounts of Fentanyl...." he wrote in the Truth Social message.

"The center of the universe today will be the White House Rose Garden where we will finally hear about reciprocal tariffs," Deutsche Bank Research said, noting that the measures will come into effect immediately.

The ICE US Dollar Index declined 0.5% to 103.77, trading close to its lowest since October.

Most US Treasury yields rose intraday, with the 10-year yield up 4.9 basis points to 4.21% and the two-year rate 4.7 basis points higher at 3.91%.

In economic news, ADP's monthly measure of private payrolls showed a 155,000 increase in March, above expectations for a 120,000 increase in a Bloomberg-compiled survey. The March gain followed an upwardly revised 84,000 jobs increase in February.

In company news, Domino's Pizza (DPZ) said it has joined DoorDash's (DASH) Marketplace platform under a new partnership with the company. Shares of DoorDash jumped 4.3% intraday, the top performer on the Nasdaq.

West Texas Intermediate crude oil futures increased 0.8% to $71.74 a barrel.