Beijing -- which has refused to grant any concessions to the protest movement -- has seized on the airport violence, with state-media churning out a deluge of condemnatory articles, pictures and videos.
Until the airport protest, hardcore demonstrators had largely focused their anger towards the police, or state institutions such as the city's parliament and Beijing's main office in the city.
The chaotic airport scenes have prompted some soul-searching within the largely leaderless movement over whether that violence has undermined their cause.
The economy, already battered by the trade war, has also been affected. The city's financial chief Paul Chan on Thursday predicted a meagre zero to one percent growth for the year.
Trump's comments on Hong Kong appeared to signal a change in his approach to events in the city.
He has come under fire from both sides of the political aisle for shying away from the issue, avoiding criticising Beijing even as he cited US intelligence reports of Chinese forces moving to the territory's border.It’s unlikely that Chinese leader Xi Jinping will follow Trump’s advice. The communist government in Beijing has been threatening to violently crack down on the demonstrations, and has been staging paramilitary exercises in nearby Shenzen in view of reporters.
Trump’s tweet, though, offered insight into his effort to balance his floundering trade talks with the growing outcry in Washington and beyond over the political crisis in Hong Kong.