The new US ambassador to Japan said Friday he was "extremely optimistic" that the two countries will agree a trade deal, after Tokyo's tariffs envoy visited Washington.
Ryosei Akazawa met President Donald Trump on Wednesday and held talks with senior US officials as Japan looks to pare back stiff levies announced by the White House.
While there was no immediate breakthrough, the next round of negotiations is scheduled before the end of the month.
"I've met now with most of the principals who are in the room and doing the negotiating... I'm extremely optimistic that a deal will get done," ambassador George Glass told reporters.
"(We) have the best and the brightest from Japan there doing the negotiations. We have the best and brightest from the United States," he said at Tokyo's Haneda Airport.
"And when I saw that President Trump then decided he was going to get involved and has now named this his top priority, that's why I have a lot of confidence that we'll get something done."
Japanese companies are the biggest investors into the United States and Japan is a vital strategic ally for Washington in the Asia-Pacific region.
But the country is subject to the same 10 percent baseline tariffs imposed by Trump on most countries as well as painful steeper levies on cars, steel and alumium.
Trump also imposed "reciprocal" tariffs on Japan of 24 percent, although these have been paused for 90 days along with those on other countries except China.
Yen strength
The talks were closely watched as a barometer of Washington's negotiations with other countries reeling from US tariffs.
Trump said after meeting Akazawa on his Truth Social platform that there had been "big progress".
Japan's Prime Minister Shigeru Ishiba warned Thursday that the negotiations "won't be easy".
But he added that Trump "has expressed his desire to give the negotiations with Japan the highest priority".
Ishiba reiterated to parliament Friday that there was still a "gap" between the two countries' positions.
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In addition to taking more US goods, Trump reportedly wants Japan to buy more US defence equipment and strengthen the yen against the dollar.
Akazawa said in Washington that the strength of the Japanese currency was not discussed.
The US president also reportedly wants Japan to pay more for hosting 54,000 US military personnel in Japan, from the current $1.4 billion a year.
"In a negotiation like this, we can say an agreement has been achieved only when we ultimately complete it as a package," Akazawa said on Friday.
Stephen Innes at SPI Asset Management said: "These talks aren't just bilateral -- they’re a global litmus test.
"Everyone from Berlin to Seoul is watching for clues on Trump's strategy. If Tokyo can cut a deal, it may set a precedent. If not, the message is clear: everyone's fair game."
Officials from Indonesia also held talks in Washington this week, while the finance minister of South Korea, a major semiconductor and auto exporter, will meet Bessent next week.