The United States broke off talks with South Korea on Tuesday after demanding Seoul raise its annual contribution for U.S. troop costs to $5 billion, over five times what it is currently paying, according to South Korean lawmakers.
U.S. President Donald Trump has insisted that South Korea pay more - and has also suggested pulling the troops out altogether.
"I understand that the U.S. is preparing to withdraw one brigade in case negotiations with South Korea do not go as well as President Trump wants," a diplomatic source in Washington with knowledge of the negotiations was cited as saying by South Korean newspaper Chosun Ilbo.
There are about 28,500 U.S. troops in South Korea. A brigade is about 3,000-4,000 troops, Chosun said, and a potential reduction would be within the bounds of the National Defence Authorization Act for fiscal year 2019, passed by the U.S. Congress.
None of the funds authorized by the act may be used to reduce the total number of U.S. military in South Korea below 22,000 unless the Secretary of Defense certifies the necessity to Congress committees.
U.S. Special Representative for North Korea Stephen Biegun said on Wednesday he believed the United States should continue to station troops in South Korea, when asked if he would continue to advocate for the presence of U.S. military personnel in the country if he is confirmed as Deputy Secretary of State."South Korea is among our most important alliance partners. That doesn't mean anybody gets a free ride. We have a tough burden-sharing negotiation that we're in the middle of with the South Koreans," Biegun said.