Foreign Minister Taro Kono meets with John Bolton, national security adviser to U.S. President Donald Trump, in Osaka in June. (Pool)

The Trump administration is seeking up to a fivefold increase in what Japan pays to support U.S. military forces based here, a U.S. government source said.

When John Bolton, national security adviser to U.S. President Donald Trump, visited Japan on July 21-22, he raised the possibility of the fivefold increase in talks with Foreign Minister Taro Kono and Shotaro Yachi, the head of the National Security Council secretariat, the source said.

While Bolton’s proposal may only be an opening gambit by the U.S. side in the expected difficult negotiations over host nation support, Trump has long complained that Japan was not contributing enough to its defense and that the U.S. military was being asked to shoulder an unfair burden.

Under an agreement reached with the United States under President Barack Obama, Japan will pay a total of 946.5 billion yen ($8.7 billion) over the five-year period from fiscal 2016 to fiscal 2020.

New negotiations on what has also been called the “sympathy budget” are expected to start next year for the period from fiscal 2021.

Trump at one time suggested he would remove all U.S. military personnel from Japan if Tokyo refused to cover all of the costs of stationing those troops in Japan.

Trump continued complaining when he visited Osaka in late June for the Group of 20 summit. He criticized the Security Treaty between the two nations as unfair and said he had repeatedly pressed Prime Minister Shinzo Abe to revise the treaty.

According to a 2004 report by the U.S. Defense Department, Japan that year contributed 74.5 percent of the costs of basing the U.S. military in Japan. The ratio was much higher than those for European nations that also host U.S. military facilities.

Given the high level of Japan’s sympathy budget, government officials had generally believed it would be difficult for Washington to request an increase in the amount that Tokyo pays.

But Bolton’s proposal shows that Trump remains intent on seeing greater Japanese expenditures for U.S. troops based here.

The sympathy budget began in 1978 after the U.S. government faced a fiscal deficit as well as a stronger yen.

After his stop in Japan, Bolton had a similar message when he visited South Korea and met with Foreign Minister Kang Kyung-wha and other officials on July 24.

According to government sources from Japan, South Korea and the United States, Bolton asked Seoul to greatly increase its expenditures for U.S. troops based there.

In 2018, Seoul paid 960.2 billion won (about 88.2 billion yen) to base U.S. troops in South Korea. For 2019, the figure was increased to 1.038 trillion won (about 95.4 billion yen), and the period covered by the expenditure was reduced from five years to one.

Bolton asked for an even greater increase for 2020. Negotiations between the United States and South Korea are also expected to be difficult.

(This article was written by Shigeki Tosa in Washington and Yoshihiro Makino, a senior staff writer, in Tokyo.)