The United States has been accused of engaging in "cognitive warfare" by releasing a photo showing senior Naval brass casually eyeing off a Chinese vessel in the South China Sea.
Tensions have been rising in the increasingly contentious waters as the US vows to counter China's military buildup in the region.
Both superpowers have deployed aircraft carrier strike groups to the East and South China Seas. China has angered the Phillipines in recent weeks by deploying hundreds of boats inside the country's 320km exclusive economic zone.
The US has strongly condemned the actions and is carrying out military exercises with the Philippines Navy from Monday (local time).
On Sunday, the US Navy released a photo which quickly made waves for what many saw as the not-so-subtle message it contained.
US naval and military journalist Chris Cavas described it as a "very unusual image".
In it, the commanding officer and executive officer of the USS Mustin destroyer can be seen watching on as China's Liaoning aircraft carrier sails nearby. The captain has his feet up in a decidedly nonchalant pose as the pair watch on.
"US Navy rarely acknowledges both its efforts to shadow Chinese ships and Chinese shadowing US ships," Cavas noted when sharing the image on Twitter.
The photo was said to be taken on April 4.
Photo a show of 'cognitive warfare'
Hong Kong-based English-language newspaper South China Morning Post (SCMP) seized on the image, suggesting the US was playing mind games by releasing the photo.
"In the photo, Commander Briggs looks very relaxed with his feet up watching the Liaoning ship just a few thousand yards away, while his deputy is also sitting beside him, showing they take their PLA counterparts lightly,” Lu Li-shih, a former instructor at Taiwan’s Naval Academy, told the SCMP.
"This staged photograph is definitely ‘cognitive warfare’ to show the US doesn’t regard the PLA (People's Liberation Army) as an immediate threat."
The aircraft carrier, USS Theodore Roosevelt, and its strike group, as well as the amphibious ship USS Makin Island are also operating in the South China Sea, US officials revealed.
Military exercises resume in face of Chinese aggression
For the next fortnight, forces from the Philippines and the US will conduct a two-week joint military exercise, rebooting the 'Balikatan' training event that was cancelled last year.
The US has no military forces based permanently in the Philippines, but sometimes rotates forces to the country under the US-Philippines Visiting Forces Agreement.
In a phone call on Sunday between Philippine Defence Secretary Delfin Lorenzana and his US counterpart, Lloyd Austin, the latter reiterated the importance of the Visiting Forces Agreement (VFA) between the two countries, according to a statement.
Philippines President Rodrigo Duterte last year unilaterally cancelled the two-decade-old VFA in an angry response after an ally was denied a US visa.
The VFA's withdrawal period has twice been extended, creating what officials say is a window for better terms to be agreed.
Relations between the US and its former Asian colony have been complicated since 2016 when Mr Duterte, who has made statements condemning US foreign policy while befriending China, rose to power.
Mr Duterte has said the US must pay more if it wanted to maintain the VFA.
However China's latest act of aggression towards the Philippines has strained relations between the two Asian nations.
The massing of Chinese vessels near the Philippines is among moves the US has criticised as efforts by Beijing to intimidate smaller nations in the region.
Do you have a story tip? Email: firstname.lastname@example.org