The U.S. Navy sailed an aircraft carrier through the South China Sea in a show of force against China in the midst of disputes over the strategically crucial trade zone.

A group of Filipino generals, officials, and journalists joined the crew of the USS Ronald Reagan to watch F/A-18 fighter jets take off and land on the massive nuclear-powered carrier as it made its way to Manila for a port call. Armed cruisers kept watch a few miles away, the Associated Press reported.

"The motto of this carrier is 'Peace through strength,'" Rear Adm. Karl Thomas, commander of Combined Task Force 70 and Carrier Strike Group Five, told journalists.

The carrier's presence sends a message as diplomatic talks continue among countries staking a claim to the tiny islands in the South China Sea, said Thomas. China, Vietnam, the Philippines, Malaysia, Taiwan, and Brunei have been in dispute over territorial claims in the area for decades, but China's recent militarization of the Spratly Islands has heightened tensions. The Chinese People's Liberation Army has built military depots and air strips on islands that were once tiny, barren plots in what experts believe is an attempt to assert Beijing's authority over the region.

“We just think that folks should follow the international law, and our presence allows us to provide that security and stability in the background for these discussions to take place,” Thomas said.

About $3.4 trillion worth of trade passed through the South China Sea in 2016, according to the Center for Strategic and International Studies. That was about 21% of all global trade that year, making the South China Sea a valuable prize for the parties involved in the territorial dispute.

Philippine President Rodrigo Duterte, who has had an on-again-off-again diplomatic relationship with the United States, recently took interest in the U.S. Navy, calling on America to park the 7th Fleet off China's coast in response to a June incident involving a Chinese vessel that rammed a Filipino fishing boat.

"I will join them, I will ride on the boat with admiral of the U.S.," Duterte said in July.

In March, Secretary of State Mike Pompeo promised the United States would continue to guarantee its existing security arrangement for the defense of the Philippines should the country be attacked.