The White House said the leaders of South Korea, the United States and Japan will discuss a “coordinated response” to the presence of North Korean troops in Russia at their upcoming trilateral summit. 

National security adviser Jake Sullivan made the remarks Thursday during a press briefing on board Air Force One en route to Peru. 

Sullivan said the summit is a chance for the three leaders to make sure their countries are “on the same page” and moving “in a coordinated way.”

Calling the North Korean troops’ presence in Russia a significant development, he said the three leaders will treat it with the seriousness it deserves. 

Sullivan also said the three nations will announce the establishment of a trilateral cooperation secretariat when the leaders meet this week.

He said the secretariat will be one of the main outcomes of the trilateral summit, providing an institutional framework for trilateral meetings in the future.