US President Donald Trump wants South Korea to contribute more to the cost of the thousands of US troops on its soil.

A $5bn 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 defence officials from the United States visit South Korea this week.

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

Trump has floated the idea of pulling US 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 legislator said last week that US officials demanded up to $5bn a year, more than five times what Seoul agreed to pay this year under a one-year deal, for stationing the 28,500 US troops in the country.

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

Gen Mark Milley, chairman of the US 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 US 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 Defence Mark Esper will visit from Thursday for the Security Consultative Meeting with South Korean Defence Minister Jeong Kyeong-doo.

‘Unacceptable, disappointing’

Randall Schriver, assistant defence secretary and Esper’s top Asia policy adviser, said the secretary did not intend to negotiate burden sharing, a job for diplomats, but he would emphasise US interests.

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

Trump has similarly accused allies, including Japan, Germany and NATO, of not shouldering their fair share of defence costs.

Separate negotiations for new defence cost-sharing deals between the US and all three are set to start next year. South Korean legislators have criticised what they called “unacceptable, disappointing” US demands.

Donald Trump arrives to speak to troops at Osan Air Base in South Korea in June; he has been complaining about the high cost of stationing American forces in South Korea [File: Susan Walsh/AP Photo]

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

A survey by the government-affiliated Korea Institute for National Unification released last week showed 96 percent of South Koreans opposed paying more for the US military presence.

“US 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 $5bn to $2bn, it’s still a tremendous burden on the South Korean administration.”

Intelligence sharing

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 spiralling 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 criticised 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.