Japanese stocks were volatile Friday morning as the yen rose as a safe haven after US President Donald Trump warned against increasing tariffs on China as the trade dispute between the two countries drove investors away.

The Nikkei rose 0.1 percent to 21,677.72 in mid-trade, the index rose 0.8 percent so far, and the broader Topix was up at 1,724.20.

Where trade tensions returned to the forefront after Trump said late on Thursday that he had instructed US trade officials to study $ 100 billion in additional tariffs on China, keeping the trade dispute between the two world economic superpowers.

US stocks futures fell on the latest news as investors worried about the devastating impact of a global trade war between the United States and China on world trade and economic growth.

In Asian trading, the dollar fell 0.2 percent to 107.15, down from a one-month high of 107.49 yen hit on Thursday.

“The market is struggling to understand what is happening with trade issues between the US and China,” said Hikaru Sato, senior technical analyst at Daiwa Securities. “It is difficult to make investment decisions when news related to this issue appears during Asian trading hours, so investors are reluctant to trade.”

Markets also focus on US job data indicators and comments from Federal Reserve Chairman Jerome Powell later on Friday.

Technology shares lost ground with Advantest Corp 2.8 percent and TDK Corp down 0.8 percent.

Shares of Seven & i Holdings rose more than 4 per cent after the company expected a 6 per cent increase in operating profit to 415 billion yen in the fiscal year ending February 2019, the eighth consecutive year of record profit.