Washington will reportedly replace its chief envoy to the stalled negotiations between South Korea and the United States on the renewal of their defense cost-sharing agreement.

Yonhap News on Monday quoted a diplomatic source as saying that current envoy James DeHart is expected to resign in the coming weeks and will likely be assigned to handle Arctic affairs. While it's uncertain who will succeed DeHart, the new envoy is expected to also lead Washington's planned cost-sharing negotiations with Tokyo.

Seoul and Washington are deadlocked on renewing the Special Measures Agreement(SMA) for the upkeep of American troops on the Korean Peninsula, which expired on December 31, 2019.

In March, DeHart and his South Korean counterpart Jeong Eun-bo had tentatively agreed on a 13-percent increase in Seoul's share, but talks fell through after President Donald Trump turned it down.

Washington is reportedly demanding Seoul increase its burden to about one-point-three billion U.S. dollars, from the 870 million dollars it paid under last year's agreement.