As the US continues its increasingly daring and extremely provocative "freedom of navigation" operations in the Strait of Taiwan and South China Sea, it's also growing more vocal about challenging China's increasingly expansionary military presence in the Pacific. Over the weekend, the US has warned Beijing that the US military would aggressively respond to provocative acts by China's coast guard and fishing boats in the same way it reacts to the Chinese navy.

The threatening posture is aimed at curbing Beijing's increasingly sharp-elbowed approach not just to the South China Sea, which it already effectively dominates, despite the rival claims of several of its neighbors (claims that have been validated by international courts), but in the Pacific more broadly, the FT reports.

Admiral John Richardson, head of the US Navy, said he told his Chinese counterpart, vice-admiral Shen Jinlong, in January that Washington would not treat Chinese fishing boats that work with the People's Liberation Army-Navy any differently from actual Navy ships. This warning wasn't unprovoked: On several occasions, Chinese fishing boats have blocked vessels belonging to the US, Vietnam and the Philippines. They have even rammed and harassed ships, blocked access to lagoons, and participated in the seizure of reefs and shoals.

"I made it very clear that the US navy will not be coerced and will continue to conduct routine and lawful operations around the world, in order to protect the rights, freedoms and lawful uses of sea and airspace guaranteed to all," Adm Richardson told the Financial Times.

China's informal marine militia has been expanding since 2015, when it established a headquarters on the Paracel Islands.

The maritime militia has been strengthened since 2015, when it created a headquarters in the China-administered Paracel Islands, a disputed area in the South China Sea that is also claimed by Vietnam and Taiwan. It has also received training alongside the Chinese navy and coast guard. In its last annual report on the Chinese military, the Pentagon said the fleet "plays a major role in coercive activities to achieve China’s political goals without fighting." China has increasingly used the maritime militia because fishing boats are less likely to prompt a military response from the US. But the latest warning significantly raises the stakes for China’s non-navy vessels engaging in aggressive acts.

Defense analysts have long warned about the need for a more effective strategy to counter Beijing's expansionary aims in the Pacific, and Andrew Erickson, a maritime militia expert at the US Naval War College, recently called for the US to "deal with China’s sea forces holistically" by demanding that both military and paramilitary ships follow international rules. He added that the US must "accept some friction and force Beijing to choose" between de-escalating or inflaming tensions.

James Stavridis, a retired US admiral and former NATO commander, said Richardson made the right call.

"It is a warning shot across the bow of China, in effect saying we will not tolerate ‘grey zone’ or 'hybrid' operations at sea," said Mr Stavridis. "A combatant is a combatant is the message, and the CNO (Chief of Naval Operations) is in the right place to warn China early and often."

As is now customary whenever the US ratchets up the pressure on the Chinese Navy, don't be surprised too see a retaliatory show of force in the coming days and weeks.