TOKYO (Kyodo) -- The Nikkei stock index briefly tumbled more than 4 percent Thursday to an eight-month low, hit by concerns over the Japanese economy after U.S. President Donald Trump unveiled a reciprocal tariff of 24 percent on the country.

The 225-issue Nikkei Stock Average fell 1,052.18 points, or 2.95 percent, from Wednesday to 34,673.69. The broader Topix index was down 87.58 points, or 3.30 percent, at 2,562.71.

The U.S. dollar weakened sharply to the upper 147 yen zone in Tokyo as the yen, seen as a safe-haven asset, was bought after Trump's announcement, dealers said.

At noon, the dollar fetched 147.79-80 yen compared with 149.30-40 yen in New York and 149.65-67 yen in Tokyo at 5 p.m. Wednesday.

The euro was quoted at $1.0912-0913 and 161.27-29 yen against $1.0843-0853 and 162.10-20 yen in New York and $1.0791-0792 and 161.49-53 yen in Tokyo late Wednesday afternoon.

The Nikkei benchmark temporarily slipped around 1,600 points to below the 35,000 threshold, as shares were sold across the board after Trump said a baseline tariff of 10 percent will be imposed on all imports and placed the much higher rate on Japan.

Kazuo Kamitani, a strategist at the Investment Content Department of Nomura Securities Co., said the tariff rate imposed on Japan was "surprising," as it was projected to be somewhere between 10 and 20 percent.

"A risk-off mood prevailed in financial markets with the additional negative news," he said.

Trump's announcement of the reciprocal tariffs came as the United States is set to impose on Thursday a 25 percent tariff on cars produced outside the country.

Some losses were later trimmed on hopes there could be room for each country to negotiate on tariff levels with the United States, brokers said.