South Korea's chief negotiator for defense cost-sharing talks with the United States has vowed his best efforts to quickly conclude the negotiations and produce a reasonable and mutually acceptable agreement. 

Ambassador Jeong Eun-bo made the pledge on Thursday as he arrived at Ronald Reagan Washington National Airport for the ninth round of talks on the eleventh Special Measures Agreement(SMA), which stipulates how much South Korea pays for the upkeep of U.S. Forces Korea. 

Jeong told reporters that he will work to resolve most of the remaining issues at the in-person negotiations. 

The chief negotiator said the countries renew a detailed SMA every five years or three years and therefore discuss various issues that surface in the process of implementing the agreement to reflect such issues.

Jeong and his U.S. counterpart Donna Welton are set to sit down for their first session in a month on Friday. It is the first time in a year that the talks will be held in-person amid the COVID-19 pandemic.