Two Chinese fighter jets ‘buzzed’ a US military reconnaissance plane in the South China Sea Tuesday in an “unsafe” manner, according to the Pentagon. 

The incident comes a week after a U.S. Navy destroyer sailed within 12 miles of China’s Fiery Cross reef, an artificial island made after months of dredging operations, more proof that tensions in the region are escalating between two global powers.

It was the third time the U.S. Navy sailed a warship close to a contested Chinese island in what the Pentagon calls “freedom of navigation” operations.

In response to China’s “unsafe” actions Tuesday, the Pentagon is “addressing the issue through the appropriate diplomatic and military channels,” according to Major Jamie Davis, a Pentagon spokesman who said the incident occurred in international airspace during a “routine” patrol by the U.S. aircraft.

In January, China landed civilian jets on a 10,000-foot runway on Fiery Cross reef, more proof that China is militarizing the South China Sea and threatening U.S. allies in the region.  

In February, China  deployed fighter jets to a contested island in the South China Sea, the same place, Woody Island, where China deployed surface-to-air missiles a week before, according to satellite imagery exclusively obtained by Fox News.

The dramatic escalation in February came as Secretary of State John Kerry hosted his Chinese counterpart, Foreign Minister Wang Yi, at the State Department.

Wang said he hoped that “close up” military flights and patrols by U.S. Navy ships over the contested islands would end.

Kerry said he wanted China to end its militarization of the contested islands in the South China Sea.

"We want to halt the expansion and the militarization of occupied features," he said.

His Chinese counterpart added that he didn't want to see any more U.S. military over flights or patrols.

"We don’t hope to see any more close-up military reconnaissance or the dispatch of missile destroyers or strategic bombers to the South China Sea," said Foreign Minister Wang.

Chinese President Xi pledged not to militarize the South China Sea when he visited the White House last fall.

In February, Adm. Harry Harris, leader of the U.S. military’s Pacific Command, told Congress that China was clearly militarizing the South China Sea. "You would have to believe in a flat earth to think otherwise," he told lawmakers.  

After the U.S. Navy guided-missile destroyer sailed past China’s artificial island last week, China scrambled fighter jets to show its displeasure.

NBC was first to report the latest incident.

Lucas Tomlinson is the Pentagon and State Department producer for Fox News Channel. You can follow him on Twitter: @LucasFoxNews