Japan's chief tariff negotiator Ryosei Akazawa arrived Tuesday night in Washington, where he will ask U.S. cabinet members to implement as quickly as possible an agreed cut in tariffs on Japanese car and auto part imports.

Akazawa's latest visit comes two weeks after he and U.S. President Donald Trump struck a trade deal under which the United States committed to lowering the so-called reciprocal tariff rate on Japanese goods, due to take effect on Thursday, to 15 percent from the threatened 25 percent.

At that time, Trump also agreed to reduce auto tariffs to 15 percent for Japan in exchange for a promise to invest massively in the United States.

However, unlike the country-specific tariff rate, it remains unclear when the Trump administration plans to implement the lowered auto tariffs.

Using a different legal framework than his reciprocal tariff scheme, Trump raised the auto tariff on U.S.-bound vehicles to 27.5 percent from 2.5 percent in April, citing national security concerns.

Akazawa, Japan's minister for economic revitalization, said before his departure that he will attempt to ensure the United States meets the terms of the bilateral agreement in the upcoming ninth round of talks with Trump's trade team.

Japanese Prime Minister Shigeru Ishiba has faced criticism from opposition lawmakers for not having signed a document with Washington to confirm the trade agreement.

Some critics have suggested there might be misunderstandings, given there are discrepancies in the Japanese and U.S. governments' descriptions of the agreement.

Under the deal, for example, Japanese officials have said imports from Japan already subject to tariffs of 15 percent or higher will not face the 15 percent duty on top.

But an executive order signed last week by Trump modifying reciprocal tariff rates, as well as other formal U.S. documents, made no mention of such a condition.

While speaking of Trump during a parliament session earlier this week in Tokyo, Ishiba said he is"not an ordinary person. He is someone who wants to change the rules."

"It is more difficult to put (an agreement) into practice than to reach an agreement," Ishiba said.

Akazawa is scheduled to stay in the U.S. capital through Friday and may hold talks with Treasury Secretary Scott Bessent and Commerce Secretary Howard Lutnick.