South Korea is home to about 28,500 U.S. troops known as U.S. Forces Korea. Cost sharing only became a feature of the alliance in 1991, when Seoul agreed to share some of the burden of stationing U.S.

South Korea's conservative presidential candidate Kim Moon-soo said on Monday he was willing to discuss sharing more of the cost of stationing the U.S. military in the country, which U.S. President Donald Trump has demanded over the years.