Citing US defence officials, the WSJ report said Washington is considering whether to move around 4,500 troops out of South Korea and deploy them to other locations, including Guam.

Washington, South Korea's long-time key security ally, stations around 28,500 troops in the South to help protect it against the nuclear-armed North Korea.

But US President Donald Trump said last year -- before winning the election -- that if he returned to the White House, Seoul would pay billions more annually to host American troops.

When asked about the WSJ report, Seoul's defence ministry said: "There has been no discussion whatsoever between South Korea and the United States regarding the withdrawal of the United States Forces Korea".

The allies last year signed a new five-year agreement on sharing the cost of stationing US troops in South Korea, with Seoul agreeing to raise its contribution by 8.3 percent to 1.52 trillion won ($1.1 billion) for 2026.

"US Forces Korea have served as a key component of the South Korea-US alliance, maintaining a strong combined defence posture with our military to deter North Korean aggression and provocations," Seoul's defence ministry said, adding this contributed to "peace and stability on the Korean Peninsula and in the region."

"We will continue close cooperation with the US to further strengthen this role going forward."

United States Forces Korea declined to comment when contacted by AFP, saying any remarks on the matter should come from Washington.