SEOUL (Reuters) - A $5 billion demand to meet the cost of hosting American troops, and tensions between Seoul and Tokyo that threaten to undercut regional cooperation are set to top the agenda when senior U.S. defense officials visit South Korea this week.

FILE PHOTO: Flanked by Secretary of Defense Mark Esper (L) and Chairman of the Joint Chiefs Army Gen. Mark Milley, U.S. President Donald Trump meets with senior military leaders at the White House in Washington, U.S., October 7, 2019./File Photo

U.S. President Donald Trump’s insistence Seoul take on a greater share of the cost of American military presence as deterrence against North Korea has tested South Korea’s confidence in the security alliance with Washington.

Trump has floated the idea of pulling U.S. troops from the Korean peninsula, which remains in a technical state of war under a truce that suspended the 1950-53 Korean War.

A South Korean lawmaker said last week that U.S. officials demanded up to $5 billion a year, more than five times what Seoul agreed to pay this year under a one-year deal, for stationing the 28,500 U.S. troops.

U.S. officials have not publicly confirmed the number, but Trump has previously said the U.S. military presence in and around South Korea was “$5 billion worth of protection”.

Gen. Mark Milley, chairman of the U.S. Joints Chief of Staff, said the American public needed an explanation why “very rich and wealthy” South Korea and Japan cannot defend themselves and why U.S. soldiers were deployed there.

Milley, who was speaking to reporters en route to Tokyo on Sunday, arrives in Seoul on Wednesday for the annual Military Committee Meeting.

Secretary of Defense Mark Esper will visit from Thursday for the Security Consultative Meeting with South Korean Defense Minister Jeong Kyeong-doo.

‘UNACCEPTABLE, DISAPPOINTING’

Randall Schriver, assistant defense secretary and Esper’s top Asia policy advisor, said the secretary did not intend to negotiate burden sharing, a job for diplomats, but he would emphasize U.S. interests.

“They have to be willing to pick up a larger share of the burden, as the president has emphasized globally, not just related to South Korea,” Schriver told a small group of reporters ahead of the trip.

Trump has similarly accused allies including Japan, Germany and NATO of not shouldering their fair share of defense costs. Separate negotiations for new defense cost-sharing deals between the United States and all three are set to start next year.

South Korean lawmakers have criticized what they called “unacceptable, disappointing” U.S. demands.

Some progressive groups in South Korea have called for a fundamental shift in the 70-year alliance with the United States, including a withdrawal or drastic reduction of U.S. troops.

A survey by the government-affiliated Korea Institute for National Unification released last week showed 96% of South Koreans were against paying more for the U.S. military presence.

“U.S. demands would get more reasonable as negotiations progress, after raising alarm with extremely high numbers,” said Shin Beom-chul, a senior fellow at the Asan Institute for Policy Studies in Seoul.

“But there’s real pressure from Trump, and even if it goes down from $5 billion to $2 billion, it’s still a tremendous burden on the South Korean administration.”

INTELLIGENCE SHARING WITH JAPAN

Esper and Milley are also expected to step up pressure on South Korea to reverse its decision to end an intelligence-sharing agreement with Japan amid a spiraling diplomatic and trade feud.

The pact, called GSOMIA, or the General Security of Military Information Agreement, is set to expire next week after Seoul decided not to renew it following Tokyo’s imposition of export controls on South Korea.

Washington has criticized the move, seeing the deal as vital to three-way cooperation in fending off North Korea’s nuclear and missile threats.

A spokesman at South Korea’s foreign ministry reiterated Seoul is willing to reconsider the decision if Japan withdraws its trade regulations.

Milley said Seoul and Tokyo should “get past some of these friction points” as those only benefit North Korea and China.