Washington also continues to stand ready to facilitate dialogue between its two Asian allies, a US State Department spokesperson told Yonhap News Agency.
"As an ally and friend to both the Republic of Korea and Japan, the United States believes it is critical to ensure strong and close relationships between and among our three countries in the face of our shared regional challenges, including those posed by the DPRK, as well as our other priorities in the Indo-Pacific and around the world," the official said, referring to North Korea by its official name, the Democratic People's Republic of Korea.
Tensions between Seoul and Tokyo have flared since Japan announced export curbs against South Korea in early July for what it described as the neighboring nation's lax export controls on sensitive materials with potential military use.
South Korea has condemned the move as retaliation for its court rulings that ordered Japanese firms to compensate Koreans forced into labor during Tokyo's 1910-45 colonial rule of the Korean Peninsula.
The row took a turn for the worse this month when Japan announced South Korea's removal from a list of trading partners given preferential treatment in export procedures.
South Korea announced Monday that it, too, will remove Japan from its own "whitelist" starting next month.
"The United States recommends Japan and the Republic of Korea find the space for creative solutions to their disagreements," the spokesperson said. "The United States will continue engaging on these issues and stands ready to facilitate dialogue between our two allies."
Washington has said that while it will encourage dialogue between Seoul and Tokyo, it will not mediate or arbitrate the dispute.
The spokesperson suggested that the two countries each suffer consequences when their ties worsen, and each bears responsibility for improving them.
"Prudence is required to prevent tensions from contaminating the economic and security aspects of Korea-Japan ties," added the spokesperson. "We are all stronger -- and Northeast Asia is safer -- when the United States, Japan, and Korea work together in solidarity and friendship."
US President Donald Trump has also expressed concern about the deteriorating ties.
"South Korea and Japan are fighting all the time," Trump told reporters on Friday. "They've got to get along because it puts us in a very bad position." (Yonhap)