A top U.S. negotiator arrived in South Korea on Sunday for a third round of defense cost-sharing talks.

Arriving at Incheon International Airport, James DeHart of the U.S. State Department told reporters that there is a lot of work for the two allies to do in order to reach an agreement that is fair and equal for both sides. 

The negotiator, however, expressed confidence that with "some hard work," the allies will reach an agreement that is mutually acceptable and that ultimately strengthens the long-standing alliance.

DeHart and his South Korean counterpart Jeong Eun-bo will sit down for two-day talks in Seoul set for Monday and Tuesday.

The allies held two previous rounds of negotiations in late September in Seoul and October in Hawaii. In the third round, the two sides are expected to discuss details based on the results of the previous negotiations. 
 
The United States is reportedly demanding South Korea pay five billion dollars, or five-point-eight trillion won, to maintain U.S. armed forces and assets on the Korean Peninsula.