A sticking point is Washington's push for a sharp increase in Seoul's contribution. This year alone, South Korea has contributed

960 billion won (US$859 million) to maintain US forces on the peninsula, a key deterrent against possible North Korean aggression.

The Wall Street Journal reported last week, citing people familiar with the SMA talks, that US President Donald Trump wants Seoul to pay as much as double its current amount, the equivalent of $1.6 billion per year for the next five years.

The grueling negotiations have been a source of tensions between the allies, as they strive to remain on the same page to facilitate ongoing diplomacy to denuclearize North Korea and establish a lasting peace regime on the peninsula.

Chang Won-sam, a career diplomat who served as ambassador to Sri Lanka, led South Korea's negotiating team and his counterpart was Timothy Betts, deputy assistant secretary of state for plans, programs and operations.

Previous SMA negotiations were held in Honolulu, Jeju, Washington, D.C., Seoul and Seattle earlier this year. (Yonhap)