TOKYO (Kyodo) -- Tokyo stocks were mixed Tuesday morning, as selling after new U.S. President Donald Trump hinted at imposing tariffs on Mexico and Canada soon erased earlier gains fueled by hopes the measures would be postponed.

The 225-issue Nikkei Stock Average rose 49.27 points, or 0.13 percent, from Monday to 38,951.77. The broader Topix index was down 1.95 points, or 0.07 percent, at 2,709.32.

The U.S. dollar hit a one-month low in the upper 154 yen zone in Tokyo, as U.S. long-term Treasury yields fell on eased concerns over inflation following a lack of tariff announcements during Trump's inauguration.

But it later bounced back to the lower 156 yen range after Trump suggested that the United States could impose 25 percent tariffs on Mexico and Canada from next month, dealers said.

At noon, the dollar fetched 155.13-14 yen compared with 155.67-71 at 4 p.m. in London and 155.98-156.00 yen in Tokyo at 5 p.m. Monday.

The euro was quoted at $1.0385-0389 and 161.10-17 yen against $1.0317-0318 and 160.93-97 yen in Tokyo late Monday afternoon. U.S. financial markets were closed Monday for a public holiday.

Stocks opened higher as automakers and other export-focused companies drew buying, buoyed by relief that Trump refrained from imposing tariffs on his first day in office, analysts said.

But the market soon turned choppy, fluctuating between negative and positive territory, as Trump's subsequent comments on Mexico and Canada reignited concerns that export-oriented firms may be adversely impacted by the new trade measures, brokers said.

"A wait-and-see mood will likely prevail until President Trump attends inauguration balls (capping off his first day) or there are further details on executive orders," said Kazuo Kamitani, a strategist in the Investment Content Department of Nomura Securities Co.