Chief of Naval Operations Adm. John Richardson said Thursday he wants more international participation in freedom of navigation operations in the South China Sea.

“It would be great if we could — because it is international law — I think a greater international participation would be something to look forward to as sort of a strategic approach to that,” Richardson said at the Brookings Institution in Washington.

Richardson, who described freedom of navigation as “an expression of our advocacy for international rules and norms,” also said U.S.-China relations could be “a fruitful area for us both to cooperate on in terms of address the North Korea threat.”

{mosads}Richardson’s remarks come a day after all 100 senators were invited to the White House for a briefing on North Korea. Top administration officials, including Defense Secretary James Mattis and Secretary of State Rex Tillerson, briefed the senators who attended.

The Trump administration has pledged to take a hard line with North Korean leader Kim Jong Un amid escalating tensions with the isolated country over its nuclear program after a failed missile launch last week.

Senators said after the meeting that they expected the administration to step up pressure on North Korea, including pressing China and others in the region to take a tougher stance against Pyongyang.

Richardson also said the Navy in the next few weeks would release an article that describes service leaders’ vision of the future Navy. The article is separate from the highly anticipated 30-year shipbuilding plan, which is expected this summer.