The U.S. State Department has reportedly reaffirmed its support of inter-Korean cooperation after a Japanese daily reported on Monday that Washington opposed Seoul's pursuit of inter-Korean economic cooperation projects. 

A spokesperson at the department reportedly told the Voice of America on Monday that the United States supports inter-Korean cooperation, adding that the department does not comment on the details of private diplomatic dialogue.

The spokesperson said the U.S. coordinates with South Korea to ensure such cooperation proceeds in lockstep with progress on denuclearization.

The Yomiuri Shimbun daily reported on Monday that Seoul's top security adviser Chung Eui-yong asked the U.S. to approve the resumption of Geumgang tours and the inter-Korean Gaeseong Industrial Complex when he met his U.S. counterpart Robert O’Brien in Washington on January 7.  

O'Brien reportedly voiced opposition, saying it requires caution to seek inter-Korean projects in disregard of United Nations sanctions against the North.

South Korea's presidential office dismissed the report as "groundless."