On Thursday, 6 April, the controversial Philippine president declared that he had ordered the Filipino military to occupy several Philippines-claimed islands in the South China Sea, in the face of ongoing Chinese activity, including land-reclamation and navy patrols.
"We tried to be friends with everybody but we have to maintain our jurisdiction now," Duterte said.
Duterte has made nationalist comments about the Philippines's territorial rights in the past, once joking that he would jet ski to a Chinese man-made island in the South China Sea to reinforce the Philippines claim. However, Beijing did not see the funny side of Duterte's military command.
"We express our concern in this regard. We hope that the Philippines will continue to handle maritime disputes with China properly," Chinese Foreign Ministry's spokeswoman Hua Chunying said on Friday, 7 April.
Also, on Friday, the Philippines Defense Minister Delfin Lorenzana hastily clarified that Manila was planning to only repair and upgrade facilities on Spratly islands that the Philippines is already occupying.
"The president wants facilities built such as barracks for the men, water and sewage disposal systems, power generators, light houses, and shelters for fishermen," Lorenzana was quoted as saying by Reuters.
The quick reversal of official rhetoric coming out of the Philippines has become a trademark of the Duterte administration, since he took office in June 2016.
Inflammatory comments, often insulting world leaders, are then re-worded or outright reversed by one of the president's spokespersons, ministers or military officials.
The speed of this particular official policy revision is a sign of how much is at stake in the South China Sea dispute.
It's estimated that around US$5 trillion of seaborne goods pass through the waters every year. There are also thought to be significant mineral resources.
China, the Philippines, Brunei, Malaysia, Vietnam and Taiwan are all claimants on parts of the waters and its islands and reefs.
Added to this is the Philippines increasing financial reliance on China, pivoting away from the US.
Since taking office, President Duterte has sought US$24 billion in investment and financing deals from Beijing.
It's now not clear what the Philippines' strategy in the region is. Currently, Manila occupies nine out of around 50 islands that they claim.
Duterte has formerly said that he might visit one island on June 12, to raise his country's national flag on the Philippines Independence Day.