Biegun came to Seoul on Tuesday for talks with senior Seoul officials over joint efforts to resume working-level nuclear negotiations between Washington and Pyongyang. He apparently extended his stay here by one day for an unspecified reason.
Biegun refused to comment when asked to share his thoughts on Seoul's decision to terminate the military pact with Japan.
Seoul announced its decision to end the pact amid a rancorous row with Tokyo over history and Japan's recent export restrictions seen as political retribution for last year's South Korean Supreme Court rulings against Japanese firms over wartime forced labor.
In a rare public rebuke, Washington expressed "strong concern" and "disappointment" over Seoul's decision on the pact. (Yonhap)