Asian stocks were mostly lower on Wednesday, as investors stayed cautious ahead of US and Japanese central bank policy decisions, while crude oil prices hovered near 2016 highs.

    Japan's Nikkei lost 0.4 percent to 17,290.49 as Japan-based suppliers of iPhone parts fell after Apple Inc. reported its first-ever decline in iPhone sales and its first revenue drop in over a decade overnight. Hong Kong's Hang Seng fell 0.4 percent to 21,312.12. 

The Shanghai Composite index fell 0.4 percent to 2,953.89. Australia's S&P/ASX 200 shed early gains, slipping 0.6 percent to 5,253.50. Taiwan stocks fell, also weighed down by a drop in shares of Apple suppliers. 

South Korea's Kospi shed 0.2 percent while Shanghai nudged up 0.1 percent. 
The euro rose to $1.1307 from $1.1297 on Tuesday. The dollar fell to 111.17 yen from 111.32 yen.