South Korea's chief negotiator in defense cost-sharing talks with the U.S. said Thursday that the two sides are not discussing the possible deployment of South Korean troops to the Strait of Hormuz in the talks.

Jeong Eun-bo made the remark to reporters at Dulles International Airport as he departed Washington following a sixth round of talks that ended without an agreement. 

Regarding Presidential Chief of Staff Noh Young-min's remarks that Seoul and Washington "significantly narrowed differences" in the latest talks, Jeong said that "new issues" always emerge in the process of negotiations. 

Asked if the new issues include the possible deployment of South Korean troops to the Strait of Hormuz near Iran, Jeong said that the two sides are not talking about the matter or anything outside the framework of the Special Measures Agreement. 

He also denied that the two sides are discussing South Korea's arms purchases, saying Seoul has simply emphasized such purchases from the U.S. to receive a fair evaluation of its contribution to the alliance.