Reuters - Wall Street futures and the dollar slid in Asia on Monday as confusion over U.S. tariffs revived the "sell America" trade, while confidence in the entire AI sector was set to be tested by results from tech-diva Nvidia this week.

Gold gained and oil prices eased ahead of another round of talks between the United States and Iran due in Geneva on Thursday, with the risk of U.S. military strikes lingering if a deal is not done.

Uncertainty loomed large after the U.S. Supreme Court struck down President Donald Trump's emergency tariffs, leading him to announce a new 10% rate on the rest of the world, only to then lift it to 15% in a move that even seemed to surprise some of his own officials.

"The tariff landscape is now more uncertain than before, uncertainty is not good news for any economy or market," said Rodrigo Catril, a senior FX strategist at NAB.

"Unless common sense prevails, we could be entering a circular process where new tariffs are announced, then potentially overturned, only for new tariffs to be announced, and we do the dance again."

It was not yet clear when these tariffs would be imposed, what might be excluded and whether every country would be slapped with 15%. Some, including the UK and Australia, had 10% tariff rates under the former rules, while many countries in Asia had higher rates.

With so much up in the air Asian markets were mixed, with MSCI's broadest index of Asia-Pacific shares outside Japan, opens new tab up 0.8% in light trade.

Japan's Nikkei, opens new tab was shut for a holiday but futures traded down 1.0% at 56,605 versus a cash close of 56,825.

The chance of lower tariffs helped South Korea, opens new tab extend its bull run with a 1.2% rise, having already jumped 5.5% last week to all-time highs. Taiwan, opens new tab followed with a rise of 1.2% to a record peak.

S&P 500 futures fell 0.7% and Nasdaq futures dropped 0.9% ahead of earnings from Nvidia, opens new tab, which are sure to cause waves given the tech behemoth makes up almost 8% of the S&P 500 index.

The world's most valuable company is expected to post a 71% rise in earnings per share to $7.76, though estimates range from as low as $6.28 to as high as $9.68. Options imply its shares could shift by at least 6% in either direction on the announcement.

The Treasury market had been sideswiped by the tariff news as it raised the risk the U.S. government would have to repay around $170 billion in revenue. Such an outcome would, on paper, widen the fiscal deficit by half a percentage point to around 6.6% of GDP.

The holiday in Japan meant cash Treasuries were not trading, but 10-year note futures were down 2 ticks.