The two days of talks in Hawaii marked the second time the allies have met to negotiate a new Special Measures Agreement on how the two sides should share the cost of the upkeep of the 28,500 US troops stationed in South Korea.

The first round of the talks took place in Seoul last month.

Details of this week's talks were not immediately available, with the foreign ministry in Seoul only saying in a mobile phone text message to reporters that the meeting between South Korea's top negotiator, Jeong Eun-bo, and his US counterpart, James DeHart, ended.

The allies have been under pressure to renew the Special Measures Agreement (SMA), amid Washington's explicit demand to its allies for "a fair share" of the cost for the US troop presence. US Secretary of Defense Mark Esper renewed that position Thursday, saying there can be "no free riders" when it comes to

common defense.

"There can be no free riders to our shared security. Regardless of geographic location, size or population all must do their part to deter war and defend the alliance," he told an event hosted by the German Marshall Fund policy think tank in Brussels. "We are only as strong as the investments we are willing to make toward our common defense."

US Secretary of State Mike Pompeo also made similar remarks in an interview with a local newspaper.

"I think it's important for people to understand that other countries have to step up too. Other countries must share the burden for not just the security of the world but security for their own countries," he said.

Seoul has suggested a "reasonable and equitable" share in response to Washington's call to pay more for the expenses.

"Our government's basic position is that the defense cost-sharing negotiations should proceed within the framework of the SMA that we have maintained throughout the past 10 SMA deals," Foreign Minister Kang Kyung-wha told a press conference Thursday.

In this week's talks, Seoul and Washington presumably faced off over a series of contentious issues, including the amount of Seoul's payments, the duration of the new SMA and other specific items that will be covered by the cost-sharing arrangement. (Yonhap)

This year's SMA, signed in March, requires South Korea to pay 1.04 trillion won ($886 million), an increase of 8.2 percent from the previous year. The current deal is set to expire Dec. 31.

Since 1991, Seoul has shouldered partial costs under the SMA -- for Korean civilians hired by the USFK, the construction of military facilities to maintain the allies' readiness and other forms of support.