US benchmark equity indexes fluctuated between gains and losses before closing mostly higher on Tuesday as investors braced for new tariff announcements by the Trump administration.

The Nasdaq Composite rose 0.9% to 17,449.9, while the S&P 500 added 0.4% to 5,633.1. The Dow Jones Industrial Average was virtually flat at 41,990. Health care and financials logged losses, while consumer discretionary led the gainers among sectors.

US President Donald Trump's planned reciprocal tariffs on other countries will be effective immediately as they are announced Wednesday, CNBC reported, citing White House Press Secretary Karoline Leavitt.

The Washington Post reported, citing unnamed sources, that White House aides have drafted a proposal that would impose tariffs of about 20% on most imports.

The recently outlined 25% tariff on auto imports will become effective Thursday, Reuters reported.

"International counterparts are understandably bracing for further economic challenges amid the latest round of levies, with the (European Union) specifically considering 'a broad range' of options to retaliate, if necessary," Stifel said in a note.

US Treasury yields moved lower Tuesday, with the 10-year rate falling 8 basis points to 4.17% and the two-year rate dropping 3.5 basis points to 3.88%.

In economic news, the US manufacturing sector fell into contraction territory in March amid weak demand, according to the Institute for Supply Management, while S&P Global (SPGI) data showed activity stalling.

"Demand and production retreated and destaffing continued, as panelists' companies responded to demand confusion," said Timothy Fiore, chair of the ISM's manufacturing business survey committee. "Prices growth accelerated due to tariffs, causing new order placement backlogs, supplier delivery slowdowns and manufacturing inventory growth."

US job openings dropped more than the projected in February, while layoffs rose, government data showed.

The Bureau of Labor Statistics is expected to report Friday that the US economy added 139,000 nonfarm jobs last month, which would mark a drop from a 151,000 gain posted for February, according to a Bloomberg-compiled survey.

West Texas Intermediate crude oil decreased 0.4% to $71.23 a barrel Tuesday.

In company news, Johnson & Johnson (JNJ) shares declined 7.6%, the biggest drop on the Dow and the S&P 500. The company said late Monday that the US Bankruptcy Court for the Southern District of Texas denied its Red River Talc unit's request to confirm its proposed prepackaged bankruptcy plan.

Electric vehicle maker Tesla's (TSLA) shares rose 3.6% Tuesday, among the top gainers on the S&P 500.

PVH (PVH) shares jumped 18%. The clothing company late Monday offered a full-year earnings outlook above market expectations on the back of better-than-expected fiscal fourth-quarter results.

Gold was little changed at $3,151.3 per troy ounce, while silver lost 0.7% to $34.39 per ounce.