U.S. President Donald Trump on Monday complained that Japan is not importing enough American rice, expressing further frustration as his administration and officials from the key Asian ally struggle to make progress toward a deal in bilateral tariff negotiations.

Axar.az informs according to Japanese media, Trump said on social media that Japan "won't take our RICE, and yet they have a massive rice shortage. In other words, we'll just be sending them a letter, and we love having them as a Trading Partner for many years to come."

In Trump's post on his Truth Social platform, which singled out Japan in a way he rarely does online, he started by saying he wanted to give an example of how "spoiled" countries have become with respect to the United States.

Japan's top government spokesman Yoshimasa Hayashi said in Tokyo that he would not comment directly on the post but noted the country has "not considered sacrificing agriculture" in the ongoing negotiations with the United States.

Trump's statement came a day after he said in a TV interview that he has no plans to roll back hefty auto tariffs that have hit Japanese carmakers, despite Tokyo's persistent opposition expressed in now-stalled tariff negotiations.

"I could send one (letter) to Japan: 'Dear Mr. Japan, here's the story. You're going to pay a 25 percent tariff on your cars,'" Trump said on Fox News.

During the interview that aired on Sunday, Trump also accused Japan of importing too few American cars. "They won't take our cars, and yet we take millions and millions of their cars into the United States. It's not fair," he said.

To curb its trade surplus with the United States, he said Japan could purchase "a lot of oil" and other goods from his country.