Japan's Finance Minister Taro Aso said Sunday he made clear to U.S. Treasury Secretary Steven Mnuchin that Tokyo opposes the automobile tariffs under consideration by Washington.

Aso told reporters he "communicated Japan's stance" to his U.S. counterpart during bilateral talks on the sidelines of a meeting of Group of 20 finance leaders in Buenos Aires.

(Taro Aso (L) and Bank of Japan Governor Haruhiko Kuroda meet the press after the G-20 meeting)

In May, U.S. President Donald Trump ordered an investigation into whether imports of automobiles and auto parts pose a "national security" threat, seen as a prelude to imposing steep tariffs.

Trump used a similar logic earlier this year to justify tariffs on steel and aluminum under Section 232 of the U.S. Trade Expansion Act. China is the main target of those tariffs, but U.S. allies such as the European Union and Japan have also been subjected to them.

Aso said he also pushed Mnuchin for exemption from the metals tariffs, but declined to say what response he got.

Mnuchin said on Twitter the two discussed "trade, investment and economic growth."

Aso, who doubles as deputy prime minister, also called on Trump's administration to exempt Japanese banks from sanctions on financial institutions that have dealings with Iran, Japanese officials said.

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