Jeong Eun-bo made the remarks Thursday following the fourth round of talks in Washington on Tuesday and Wednesday over how to share the cost of stationing the 28,500-strong US Forces Korea under the cost-sharing accord, called the Special Measures Agreement.
"At this point, we are in a situation where we need to continue to narrow our differences. It is not that we have reached a concrete result," Jeong told reporters at Dulles International Airport.
"It is right to say that the US maintains its position," he added.
The US has reportedly demanded a fivefold increase in Seoul's financial contributions to $5 billion next year to cover expenditures related to the allies' combined military exercises and support for the USFK troops' families.
Under this year's SMA, which is set to expire at the end of the year, Seoul agreed to pay about $870 million.
Jeong reiterated Seoul's position that the negotiations should proceed strictly within the SMA framework, which calls for Seoul to pay partial costs for South Korean employees in USFK installations, the construction of some military facilities and logistical support.
Asked whether it would be difficult to strike a deal before the end of the year, Jeong simply said, "We will try hard to conclude the negotiations by the year's end."
After the two-day negotiations, Jeong agreed to meet with his US counterpart James DeHart again in Seoul this month to continue the negotiations. (Yonhap)