Wall Street stocks rocketed to close solidly higher on Wednesday, with dramatic advances on all three major indexes as US President Donald Trump delayed steep new tariffs hours after they took effect.

The Dow Jones surged 7.9 percent to 40,608, and the S&P 500 rallied 9.5 percent to 5,456.

The Nasdaq jumped 12.2 percent to 17,124.

All three indexes bounced on Wednesday afternoon as Trump announced a 90-day pause in country-specific tariffs that came into place earlier that day, except levies on Chinese goods.

Affected US trading partners, excluding China, would instead face a 10 percent tariff rate, temporarily reverting to a level that took effect over the weekend, though that already roiled markets.

Trump singled out the world's second biggest economy, however, saying its tariff rate would be raised to a prohibitive 125 percent "based on the lack of respect that China has shown to the world's markets."

"When markets are pricing in worst-case scenarios, it doesn't take much good news to turn that opinion around," said Art Hogan of B Riley Wealth Management.

He added that investors were waiting for any sense of a more reasonable trade process, saying this situation might "be less of a drag on economic activity and earnings."

But he cautioned that "China will become hyper-aware of the fact that they're now being isolated in this process." (AFP)