Japanese auto exports to the United States fell by almost a quarter in May, data showed on Wednesday, as concerns over Donald Trump's tariffs continued to grow and no deal has yet been struck between Tokyo and Washington.

Roughly eight percent of jobs are linked to the auto industry in Japan, home to the world's best-selling automaker Toyota as well as Honda, Nissan and other giants.

The country is seeking relief from 25 percent U.S. vehicle tariffs and other trade levies, but no agreement has been reached despite several rounds of negotiations with Trump and his administration.

Japan recorded a trade deficit for the second straight month in May, with imports exceeding the value of exports by 637.6 billion yen ($4.4 billion).

Specifically for the United States, exports declined about 11%, with auto exports down 24.7% year-on-year, according to Treasury data.

"A series of tariffs imposed by the United States, which account for roughly a quarter of global GDP and approximately 20 percent of Japan's exports, are hitting the profits of many Japanese companies," Prime Minister Shigeru Ishiba told reporters in Canada after the G-7 summit.

The situation "could have a serious impact on Japan and the United States, as well as the global economy, directly and indirectly," he warned. 

Ishiba held private talks with Trump on Monday, but no breakthrough in the trade standoff was announced.

"Because there are still some points on which both sides disagree, we have not reached agreement on the package as a whole," he said.

"I had frank discussions with President Trump and we agreed to instruct the relevant cabinet members to pursue further talks."

Japan's trade surplus with the United States shrank 4.7 percent year-on-year in May, the first contraction in five months, even as the country's imports fell 13.5 percent.

Japan, a key U.S. ally and its biggest investor, is subject to the same 10 percent base tariffs imposed on most countries, plus higher taxes on autos, steel and aluminum.

Trump also announced an additional 24 percent "reciprocal" duty on Japan in early April, but later suspended it along with similar measures on other countries. I AFP, BGNES