The United States welcomed the agreement reached between Japan and South Korea on the issue of comfort women, saying it would promote healing and help improve ties between two of Washington's most important allies.
US Secretary of State John Kerry applauded the leaders of both countries for "having the courage and vision" to reach agreement on the issue of Japan's imperial past, which has long strained relations between the two neighbours.
The tension has been a source of frustration for the US, which prefers its East Asian allies to cooperate without underlying issues getting in the way.
"We look forward to continuing to work with both countries on regional and global issues, including advancing our economic ties and security cooperation," said Mr Kerry in a statement.
A senior state department official in a media briefing likened the deal to the 12-nation Trans-Pacific Partnership trade pact, calling it "strategically consequential" as it opens doors to a new era of cooperation.
The official also said the US had played a "constructive role" in fostering an atmosphere for the agreement, citing efforts by President Barack Obama, Vice-President Joe Biden and Mr Kerry, among others.
"We have shared out best advice; we've underscored the benefits to us and to everybody in reaching an agreement, and we've worked quietly to, where possible, prevent or resolve misunderstandings between the two," said the official.
Last year, Mr Obama hosted a trilateral summit to discuss regional security on the sidelines of the Nuclear Security Summit in The Hague. The meeting marked the first official high-level meeting between South Korean President Park Geun Hye and Japanese Prime Minister Shinzo Abe.
And in October, when Ms Park visited Washington, DC, she hinted at the possibility of holding a bilateral meeting with Mr Abe, softening her tone from two months earlier, when she said a speech by Mr Abe on the 70th anniversary of World War II left "much to be desired".
On how the deal would help US security interests, the senior state department official said: "Presenting a fully united front unencumbered by the unresolved legacies of the past is a huge improvement."
National Security Adviser Susan Rice added in a statement that the US looks forward to "advancing trilateral security cooperation".
US experts said it would be important for Seoul and Tokyo to push back against nationalistic sentiments in both countries.