TOKYO (Kyodo) -- Japanese Finance Minister Katsunobu Kato on Tuesday struck a cautious tone regarding a U.S. proposal to raise tariffs on China and India for continuing to buy Russian oil as part of pressure on Moscow over its war in Ukraine.

"It is difficult to impose higher tariffs on certain countries solely for purchasing Russian oil," Kato said at a press conference, days after the United States urged fellow Group of Seven members to do so.

"Japan will fully consider what steps would be most effective" to boost pressure on Russia to bring peace to Ukraine, which has been under invasion from its neighbor since February 2022, Kato added.

During an online meeting of the G7 finance chiefs late last week, U.S. Treasury Secretary Scott Bessent told his counterparts, including Kato, that their nations should join Washington in imposing tariffs on those buying Russian oil, the United States said.

The emergency virtual meeting was convened as U.S. President Donald Trump has expressed frustration with his Russian counterpart Vladimir Putin, who has shown little interest in meeting Ukrainian President Volodymyr Zelenskyy to discuss peace terms.

As Russia relies on crude oil revenue to fund the ongoing war, it would be hit hard if higher tariffs prompt China and India to cut their purchases. The Financial Times reported that Washington has proposed tariff hikes of up to 100 percent.

The G7 comprises Britain, Canada, France, Germany, Italy, Japan and the United States, plus the European Union.