A senior U.S. official repeated on Thursday that the United States has been "very flexible" in defense cost-sharing negotiations with South Korea and that negotiations have not stopped. 

Clarke Cooper, assistant secretary of state for political-military affairs, said during a virtual press briefing that the U.S. has certainly seen itself as very flexible on being able to adjust as it proceeds through the negotiations.

Cooper said that the two sides are "still communicating" and it has been a healthy back and forth. 

The official said that it's recognized that there is need to get to a place that is "fully acceptable" for both governments and for President Trump and President Moon Jae-in. 

He added that the U.S. will keep working to achieve the goal, stressing that the U.S.-South Korea alliance is a tremendous investment and the commitment to the alliance is the bedrock of the negotiations. 
 
Seoul and Washington remain apart on how much they should each pay for the upkeep of American troops on the Korean Peninsula. The U.S. recently demanded one-point-three billion dollars a year -- a nearly 50 percent increase from last year -- while South Korea proposed that it can raise its contribution by 13 percent.