SEOUL - Republic of Korea and the United States on Tuesday started talks on how to share the defense costs of US forces stationed in ROK, according to Seoul's foreign ministry.

The two-day negotiations were launched in central Seoul to reach a new deal on ROK's financial contribution to the US Forces Korea.

The negotiation period can be extended, if necessary, as the current deal was set to expire by the end of this year, the Seoul ministry said.

In consideration of the time needed for the parliamentary approval, the talks are required to be wrapped up within this month.

ROK paid about 960 billion won (850 million US dollars) this year to share cost for the US troops stationed here, but the US side demanded raising the share to as much as 1.5 trillion won (1.3 billion US dollars), according to local media reports.

About 28,500 US troops are stationed in ROK as a legacy of the 1950-53 Korean War, which ended with armistice.

The ROK's side was led by Chang Won-sam, a career diplomat who served as ambassador to Sri Lanka, and the US side was headed by Timothy Betts, deputy assistant secretary of state for plans, programs and operations.