By Kevin Buckland

TOKYO (Reuters) - Asian stocks were heavy on Wednesday as investors fretted over what countries could be targeted for tariffs under incoming U.S. President Donald Trump, a day after he pledged new levies on Canada, Mexico and China.

The loonie and peso remained weak following sharp drops to multi-year lows on Tuesday, while the yuan edged back towards the previous session's four-month trough.

Australia's dollar, which is often used as a liquid proxy for the yuan given China is the country's biggest trading partner, also inched back towards Tuesday's four-month low.

However, the New Zealand dollar rebounded from its own multi-month lows after the country's central bank opted to cut interest rates by 50 basis points on Wednesday, disappointing some in the market who had bet on a bigger reduction.

The safe-haven yen extended its strong run, climbing to a two-week high on the U.S. dollar, which was in turn weighed down by sagging Treasury yields.

Japan's Nikkei was a stand-out underperformer again on Wednesday, declining 0.9%. The autos sector was the worst-performing industry group on the Tokyo Stock Exchange, dropping more than 3% as both the threat of tariffs and the drag of a stronger yen weighed on the profit outlook.

Taiwanese stocks lost 0.2%, while South Korea's KOSPI rose less than 0.1%, struggling to bounce back from Tuesday's 0.6% slide.

Mainland Chinese blue chips sank 0.4%, although Hong Kong's Hang Seng managed a 0.1% rise.

MSCI's broadest index of Asia-Pacific shares drooped 0.1%.

Weakness in Asian equities contrasts with gains for all three of the major Wall Street bourses overnight, and S&P 500 futures pointed to a further 0.1% advance.

Trump posted on his Truth Social platform early in Asia's Tuesday that he would immediately put a 25% tariff on all products from Mexico and Canada upon taking office, and slap an additional 10% tariff on goods from China. He said those levies would remain until the countries clamped down on issues such as illicit drugs and migrants crossing U.S. borders.

"The theme on the day has been to buy America, and for some to begrudgingly open a Truth Social account, with confirmation that headline risk and the communication channels for price discovery in markets have officially evolved," said Chris Weston, head of research at Pepperstone.

Compared with Trump's first time in office, "he is far more prepared, has a clear game plan, and has the legal passage to execute without constraint," Weston said. "Markets now expect bold action ongoing, with the noise in markets officially increasing even before inauguration."