South Korea will have to pay more than it recently offered in a defense cost-sharing pact with the US, experts said Wednesday, as US President Donald Trump continues to insist on a drastic hike in contributions from Seoul.

Trump said Monday that he had rejected an offer from Korea, which reportedly promised 13 percent more than the $900 million it paid last year. Washington had initially asked for $5 billion.

“Trump is telling negotiating teams -- both Washington and Seoul -- that he wants to see a bigger hike,” said Go Myong-hyun, a fellow at the Asan Institute for Policy Studies. “He also wants other partners like Japan and NATO to hear that they’d have to share a greater burden of bilateral defense costs than previously.”

The defense cost-sharing pact covers the upkeep of the 28,500 American troops stationed here, including the salaries of 9,000 Korean nationals working for the US military.

Half the employees were put on unpaid leave on April 1 because no agreement was in place. Washington had turned down Seoul’s offer to negotiate a side agreement dealing just with the employees.

Experts said there is little hope of clinching a new agreement in the coming days, as Trump expects Korea to offer much more than it proposed earlier to meet the $5 billion threshold.

“Trump is clearly pushing for a higher number. But it won’t go near the $5 billion. Even he knows that just won’t happen,” said Cho Han-bum, a senior analyst at the Korea Institute for National Unification.

Cho said the US would trigger strong backlash from the Korean public and could scuttle the cost-sharing negotiations if it actually pressed Seoul to pay close to $5 billion.

“Trump wants a hike drastic enough to tell his people that he’s collecting what he thinks is rightfully owed,” he said.

By Choi Si-young (siyoungchoi@heraldcorp.com)