James DeHart, U.S. Department of State's a senior advisor for security negotiations and agreements bureau of political-military affairs, speaks after a meeting with South Korean counterpart on the Special Measures Agreement (SMA) at the public affairs section of the U.S. Embassy in Seoul, South Korea November 19, 2019. POOL/REUTERS

Seoul — A U.S. negotiator cut short talks with South Korea on Tuesday over the amount that Seoul contributes to maintain the American military presence on the divided Korean peninsula. Senior negotiator James DeHart ended his delegation's participation in the talks after less than two hours on Tuesday, saying "the proposals that were put forward by the Korean team were not responsive to our request for fair and equitable burden sharing."

Just as he has done with America's NATO allies in Europe, President Trump has pushed for U.S. partners in Asia, including South Korea, to bear more of the financial burden associated with maintaining a significant American troop presence.

DeHart said the negotiations were on hold, "in order to give the Korean side some time to reconsider."

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The talks in Seoul were aimed at hammering out the next iteration of the "Special Measures Agreement," the formal document that lays out funding for the American military deployment in South Korea. The current SMA is set to expire at the end of this year.

There are about 28,000 American forces based in South Korea, where the U.S. has remained engaged since hostilities in the Korean War ended with an armistice in 1953. As no peace treaty has ever been signed, the two sides technically remain at war. The border between the two Koreas — heavily guarded by U.S. and Korean troops — is one of the most militarized patches of ground on the planet.

The Trump administration has not said how much more it wants South Korea to pay to keep the American troops there, but visiting the country last week Secretary of Defense Mark Esper said the "wealthy" host nation could afford a "substantial increase." He did not explicitly deny reports that the White House is seeking a near-five-fold increase in Seoul's contribution, to about $5 billion.

Shortly after DeHart walked out of the talks on Tuesday, top South Korean negotiator Jeong Eun Bo said there was "a significant difference between the overall U.S. proposal and the principles that we want to engage in."

The SMA is up for renewal at a crucial juncture for U.S. policy, and for South Korea. The most recent rounds of talks between the Trump administration and the regime of Kim Jong Un, aimed at ending the nuclear standoff with North Korea, failed to yield results.

Kim has repeatedly warned that he will give diplomacy until the end of this year, at which point he could return to his previous aggressive stance, carrying out nuclear and long-range missile tests.

Although U.S. officials have not said so publicly, there have been rampant rumors in South Korea that the Trump administration could decide to greatly reduce or even withdrawal the American military presence in the country unless Seoul meets financial demands.