Tokyo stocks closed at three-month lows Thursday on investor jitters a day before a US deadline to impose tariffs on Chinese imports.

The key Nikkei 225 index slipped 0.78 percent or 170.05 points to end at 21,546.99, while the broader Topix index was down 1.01 percent, or 17.05 points, at 1,676.20.

The benchmark Nikkei dropped for the fourth straight day, ending at its lowest close since early April as Chinese stocks tumbled.

“There is a strong sense of uncertainty with both the United States and China poised to impose additional tariffs” on each other’s products, said Okasan Online Securities chief strategist Yoshihiro Ito.

The United States is due to begin enforcing tariffs Friday on more than $30 billion in Chinese imports as retribution for what Washington describes as Beijing’s theft of American technology and other unfair trade practices.

Beijing has vowed to respond with its own tariffs immediately, which Trump has said will invite far steeper US counter-measures, potentially covering another $400 billion in Chinese goods.

The dollar was changing hands at 110.58 yen against 110.54 yen in London on Wednesday.

In trade in individual stocks, Sony fell 3.39 percent to 5,344 yen and Nippon Steel & Sumitomo Metal lost 1.21 percent to 2,070 yen.

Uniqlo clothing chain operator Fast Retailing fell 2.52 percent to 47,500 yen.

Automakers gave up early gains and closed lower, with Nissan down 0.33 percent at 1,042 yen and Toyota off 0.16 percent at 7,086 yen.