Technology shares took an additional hit following a sell-off in AI darling Nvidia and other so-called "Magnificent Seven" Wall Street mega-cap stocks, as investors judged the chipmaker's earnings report harshly a day after it was released.

The safe-haven yen and Swiss franc strengthened, with Japan's currency getting an additional boost from lower US Treasury yields.

An overall firmer dollar weighed on commodities including gold, although oil held on to most of Thursday's strong gains spurred by US President Donald Trump's cancellation of Chevron's Venezuela licence.

Trump said on Thursday that 25 percent duties on imports from Canada and Mexico will come into effect on March 4 - not April 2 as he had suggested the day prior - and said goods from China will be subject to an additional 10 percent duty. He also this week promised 25 percent tariffs on shipments from the European Union.

"A market that had reduced its sensitivity to recent tariff headlines has had to reconsider that reaction function," said Chris Weston, head of research at Pepperstone.

"The cleanest reaction has been seen in the FX channels," he said, noting the hit to the Canadian dollar and the euro.

Japan's Nikkei tumbled 2.4 percent early in Friday's session, buckling under the weight of a stronger yen, while South Korea's Kospi sank 1.8 percent and Australia's stock benchmark sagged 0.9 percent.

Chinese equities fared relatively better in early trading, with Hong Kong's Hang Seng down 1 percent and mainland blue chips down 0.3 percent.

Many analysts project that Trump's trade policies raise the odds of additional stimulus from next week's meeting on China's National People's Congress.

Pan-European STOXX 50 stock futures pointed 0.8 percent lower, after bourses around the region retreated on Thursday.

US S&P 500 futures were flat following a 1.6 percent tumble for the cash index overnight.

World stocks are on track for their worst week since mid-December, slumping more than 2 percent.

The US dollar index – which gauges the greenback against six major peers including the euro, yen and franc – edged down to 107.20, but started the session at the highest since February 19 at 107.34.

The euro was steady at $1.04 after earlier dipping to $1.0389 for the first time since Feb. 13.

The Swiss currency gained slightly to 0.8986 francs per dollar, bouncing off Thursday's low of 0.9005 francs.

The yen climbed 0.3 percent to 149.34 per dollar, with 10-year Treasury yields - which the currency pair tends to follow - sinking as low as 4.2310 percent in Asian hours, a level last seen on December 11.

While the threat of escalating tariffs has spurred dollar strength, it has also stoked worries about its impact on the US economy.

Recent US data has been soft, and traders have reacted by pricing in at least two quarter-point Federal Reserve interest rate cuts this year, with the first as early as June and another as soon as September.

Investors will be keeping a close watch on the Fed's preferred inflation gauge - the PCE deflator - set for release later in the day. Monthly non-farm payrolls figures are due a week from now.

Gold was flat at $2,880 per ounce, not far from Thursday's low of $2,867.63, a two-week nadir.

Oil prices held close to Thursday's peaks, with US West Texas Intermediate crude futures easing 0.4 percent to $70.08, from as high as $70.54 in the prior session.

Cryptocurrency bitcoin slid 3.6 percent to $81,260, after earlier touched $81,807.29 for the first time since Nov. 11