TOKYO: Tokyo stocks closed lower Friday with investors cautiously awaiting a speech by Fed Chair Jerome Powell for clues on plans to roll back the US central bank's stimulus measures.

The benchmark Nikkei 225 index fell 0.36 percent, or 101.15 points, to 27,641.14. Over the week, however, it gained 2.3 percent.

The broader Topix index slipped 0.34 percent, or 6.58 points, to 1,928.77 but rose 2.6 percent from a week earlier.

"Investors were more cautious than expected ahead of Jackson Hole," said Shinichi Yamamoto, a broker at Okasan Securities.

Powell is due to deliver a speech later Friday at an annual symposium of central bankers at Jackson Hole in the US state of Wyoming.

Although a major announcement is not anticipated, investors will analyse his address to gauge the future of the Fed's massive emergency financial support programme.

Trading is expected to remain cautious for now, as "the next focus will be US jobs data released next week," Yamamoto said.

The dollar stood at 109.97 yen in Asian afternoon trade, compared with 110.04 yen.

Takeda lost 0.46 percent to 3,648 yen, falling for a fourth straight session after the drugmaker and the government said Japan would halt the use of more than one million doses of Moderna's Covid vaccine, following reports of contamination in several vials.

Takeda is in charge of sales and distribution of the Moderna shot in Japan.

Nintendo dropped 1.48 percent to 51,770 yen and Sony lost 0.57 percent to 11,230 yen.

Toyota fell 0.49 percent to 9,460 yen but Nissan rose 0.54 percent to 569.1 yen.