Obed Eshun 
The US and the Philippines are holding their largest-ever joint military drills a day after China concluded large-scale exercises around Taiwan.
Beijing staged three days of drills simulating blockades of Taiwan in response to the island’s leader meeting the US House Speaker last week.
The US had called on Beijing to show restraint. Meanwhile, Taiwan’s President Tsai Ing-wen on Monday said China’s actions were “irresponsible”.
The US drills were earlier scheduled.
Both the US and Philippines flagged last month that their annual Balikatan exercise would be their largest-ever, after Washington earlier this year secured a new defence deal with the South-East Asian nation.
In February, Washington succeeded in signing off on an agreement where four new naval bases will be established on Philippine islands.
The waterways around the Philippines and around South-East Asia are among the busiest in trade, and have been the subject of disputed territorial claims by China.
On Monday, as China was concluding its large-scale drills where it deployed fighter jets and an aircraft carrier around Taiwan, the US sent a naval destroyer through the South China Sea in what it called a freedom of navigation mission.
The US sent the USS Milius past the Spratly Islands- which lie in the Philippines’ exclusive economic zone but are claimed by Beijing.
China on Monday warned that US-Philippines military cooperation should not interfere with disputes in the hotly contested waters.
“[It] must not interfere in South China Sea disputes, still less harm China’s territorial sovereignty, maritime rights and interests and security interests,” Chinese foreign ministry spokesman Wang Wenbin said on Monday.
Beijing’s drills concluded on Monday. Afterwards, Taiwan’s defence ministry said it would not stop strengthening its combat preparedness.
President Tsai in a Facebook post on Monday night also defended her trip to the US and condemned China’s military aggression as “irresponsible actions of a regional power”.
Tuesday’s drills will see the involvement of more than 17,000 troops – 12,000 from the US and 5,400 from the Philippines.
More than 100 members of Australia’s navy will also take part in the drills which run until 28 April while military personnel from 12 other countries will also participate as observers.
A front row seat to monitor China
The US is seeking access to places where “light and flexible” operations involving supplies and surveillance can be run as and when needed, rather than bases where large numbers of troops will be stationed.
In February, Washington secured access to four additional military bases in the Philippines – a deal that helped the US stitch the gap in the arc of alliances stretching from South Korea and Japan in the north to Australia in the south.
The missing link had been the Philippines, which borders two of the biggest potential flashpoints – Taiwan and the South China Sea.
One of the bases they now have access to faces Taiwan, the second the Scarborough shoal, and the third the Spratly Islands. US troops will come in small groups and on rotation.
The aim, analysts say, will be to deter further territorial expansion by China in the South China Sea, while also providing a place for the US to watch Chinese military movements around Taiwan.
With increasing concern about a conflict over Taiwan, the Philippines could offer a “rear access area” for US military operations, or even a place to evacuate refugees.
Read more from our correspondent on the significance of the US-Philippine alliance here