Tokyo stocks closed lower Wednesday as investors were concerned about the ramifications of U.S. President Donald Trump deciding to withdraw the United States from the Iran nuclear deal.

The 225-issue Nikkei Stock Average dropped 99.81 points, or 0.44 percent, from Tuesday to close the day at 22,408.88.

The broader Topix index of all First Section issues on the Tokyo Stock Exchange, meanwhile, lost 6.91 points, or 0.39 percent, to finish at 1,772.91.

Market strategists here said that investors were in a risk averse mood following Trump's decision on the Iran nuclear deal, with concerns rife about the potential geopolitical and economic affects of the move henceforth.

Brokers here also said the move by the United States has already seen oil prices spike and there is speculation by leading economists that the ramifications of the move could work out badly for the United States itself, with worsening corporate earnings and a negative overall economic impact.

But the yen depreciating against the U.S. dollar following Trump's decision for the United States to exit from the nuclear deal with Iran, saw the market's downside supported and losses trimmed, brokers here also noted.

By the close of play, pharmaceutical, electric power and gas, and precision instrument-linked issues comprised those that declined the most, and falling issues beat rising ones by 1,237 to 754 on the First section, while 92 ended the day unchanged.

On the main section on Wednesday, 1,727.43 million shares changed hands, rising from Tuesday's volume of 1,655.80 million shares.

The turnover on the third trading day of the week came to 2,926.4 billion yen (26.68 billion U.S. dollars).