Pentagon officials confirmed to The Wall Street Journal that they had canceled a “freedom of navigation” exercise planned for April that was intended to make a statement against China’s growing colonization of the region.

The decision not to conduct the exercise – which typically consists of a U.S. Navy ship traveling through international waters claimed exclusively by China – was an attempt to “lower the temperature” of the dispute between China and its neighbors over the region. China insists it has exclusive domain over most of the South China Sea, including parts of Malaysia, Brunei, the Philippines, Taiwan (which it does not recognize as a sovereign state), and Vietnam.

To aids its allies, the United States has conducted two freedom of navigation operations in the region recently, and promised to conduct them “regularly” to keep China from usurping more territory.

The Wall Street Journal reports that, instead of that operation, six American warships flew near the Scarborough Shoal in late April. The Shoal is a Philippine territory the Chinese government seized by force in 2012. Evidence of elevated assessment activity on the shoal indicates China may begin to construct civilian or military infrastructure on the shoal. The planes flew out of one of America’s newest bases in the field: the Philippines’ Clark Air Base.

The Chinese government has built artificial islands, lighthouses, plane landing strips, and air bases in disputed territory in the Spratly and Paracel Islands, contested by both the Philippines and Vietnam, in the past two years. It has also placed fighter jets and surface-to-air missiles on select islands in both archipelagos.

The Diplomat, a military analysis site, suggests that the United States’ decision to step down from a freedom of navigation operation may suggest that the Pentagon and White House are not in accord with how to approach China’s growing colonization of the region. The publication also deems the flights significantly less of a statement based on the Chinese government’s reaction to them alone, noting that the Chinese Foreign Ministry called them “nothing strange” and condemned those engaging in “high-profile hyping of such a flight.”

In contrast, a piece in the Chinese state-run Xinhua publication Thursday calls freedom of navigation exercises “political and military provocations against China and could easily lead to unexpected incidents,” threatening to attack American military assets if they get too close to China’s conquered artificial land. Such exercises, the Foreign Ministry alleges, result in “destabilizing regional peace and undermining coastal nations’ security interests.”

On Thursday, Xinhua also touted an ominous new Chinese plan “for international cooperation in the South China Sea … to cover the next five years,” though it did not provide any details.

The U.S. government engaged in its first such recent exercise in October, when the USS Lassen sailed within twelve nautical miles of the Spratly Islands. The Chinese government alleged the exercise “has threatened China’s sovereignty and security interest, and has put the safety of personnel on the reefs in danger.”

In February, the USS Curtis Wilbur engaged in a similar exercise, which China’s Foreign Ministry called “dangerous and irresponsible.”

Since then, the United States has signed a new military deal that allows American troops to use bases like the Clark Air Base and allows for at least 300 American troops to be in the Philippines at any given time. Upon the announcement of the deal, Secretary of Defense Ashton Carter announced from the Philippines that freedom of navigation exercises, in conjunction with Manila, would begin occurring “regularly.”

The Philippines is in a state of political flux, however, heading towards a presidential election to replace incumbent President Benigno Aquino on May 9. The Pentagon may have canceled the operation as a precautionary measure in light of potentially hostile forces taking over in Manila. The current frontrunner in the race, Davao City Mayor Rodrigo Duterte, threatened to cut off diplomatic relations entirely with the United States after the nation’s ambassador to Manila condemned a joke he made about a gang-rape victim. He has also asserted that he would never commit troops to any military struggle against China, as it would result in “a slaughter.” In the most recent presidential debate, he promised to personally retake the Spratly Islands on a jet-ski before sending Philippine troops to defend the territory.