Officials have signed a short-term agreement to boost South Korea’s contribution toward the upkeep of US troops on the peninsula, after a previous deal lapsed amid US President Donald Trump’s call for the South to pay more.

About 28,500 US troops are stationed in South Korea, where the United States has maintained a military presence since the 1950-53 Korean War.

The new deal must still be approved by South Korea’s parliament, but it would boost its contribution to 1.03 trillion won ($1.3 billion) from 960 billion won in 2018.

Unlike past agreements, which lasted for five years, this one is scheduled to expire in a year, potentially forcing both sides back to the bargaining table within months.

US representative Timothy Betts and Foreign Minister Kang Kyung-wha prepare to talk figures in Seoul on Sunday. Photo: Getty

“It has been a very long process, but ultimately a very successful process,” South Korean Foreign Minister Kang Kyung-wha said at a meeting before another official from the foreign ministry initialled the agreement.

While acknowledging lingering domestic criticism of the new deal and the need for parliamentary approval, Kang said the response had “been positive so far”.

The US State Department senior adviser for security negotiations and agreements, Timothy Betts, met Kang before signing the agreement on behalf of the United States, and told her the money represented a small but important part of South Korea’s support for the alliance.

“The United States government realises that South Korea does a lot for our alliance and for peace and stability in this region,” he said.

The allies had struggled to reach a breakthrough despite 10 rounds of talks since March, amid Trump’s repeated calls for a sharp increase in South Korea’s contribution.

South Korean officials have said they had sought to limit its burden to one trillion won and make the accord valid for at least three years.