Asia stocks declined on Wednesday as U.S. President Donald Trump threatened to raise tariffs on Chinese goods if the two economic powerhouses do not strike a deal.

Mainland Chinese stocks ended the day lower, with the Shanghai composite down 0.78% to 2,911.05 and the Shenzhen component shedding 0.82% to 9,809.05. The Shenzhen composite was around 0.707% lower at 1,635.16. Hong Kong's Hang Seng index slipped about 0.73%, as of its final hour of trading.

The People's Bank of China released its new loan prime rates earlier on Wednesday. The 1-year and 5-year loan prime rates were cut by 0.05% each from a month earlier to 4.15% and 4.8%, respectively.

Elsewhere, Japan's Nikkei 225 slipped 0.62% to close at 23,148.57 while the Topix index shed 0.33% to 1,691.11. On Wednesday, Japanese merchandise trade data for October from the Ministry of Finance showed exports for the month fell 9.2% year-on-year — well off the 7.6% year-on-year decline expected by economists in a Reuters poll.

The S&P/ASX 200 in Australia declined 1.35% to close at 6,722.40 as the heavily-weighted financial subindex fell 2.15%. Shares of Australia's so-called Big Four banks declined: Commonwealth Bank of Australia fell 1.33%, Westpac dropped 3.31%, Australia and New Zealand Banking Group shed 2.05% and National Australia Bank slipped 3.12%.

The moves in the sector came after Australia's anti money-laundering and terrorism financing regulator filed for civil penalty orders against Westpac.

"It is alleged that Westpac's oversight of the banking and designated services provided through its correspondent banking relationships was deficient," the Australian Transaction Reports and Analysis Centre (AUSTRAC) said in a media release.

South Korea's Kospi shed 1.3% to close at 2,125.32 as shares of industry heavyweight Samsung Electronics and chipmaker SK Hynix dropped 2.8% and 3.05%, respectively.

Overall, the MSCI Asia ex-Japan index traded 0.66% lower.