Japan's Nikkei share average tumbled to a four-month closing low on Thursday after signs the US Federal Reserve may start cutting its king-sized balance sheet earlier than expected spooked the market.

The Nikkei dropped 1.4 per cent to 18,597.06, the lowest close since early December.

Investors were also wary ahead of a potentially tense meeting between US President Donald Trump and his Chinese counterpart Xi Jinping, the first between the world's two most powerful leaders.

The broader Topix dropped 1.6 per cent to 1,480.18