Twitter has added an unprecedented warning to a Trump tweet, warning users that the post "glorifies violence".
The message was added to a post in which Mr Trump seemed to threatened that people protesting against the death of an unarmed black man in custody could be shot.
"This Tweet violated the Twitter Rules about glorifying violence," the message reads. "However, Twitter has determined that it may be in the public’s interest for the Tweet to remain accessible."
The decision comes as Mr Trump signed a new executive order on social networks. Mr Trump's announcement that social media companies would be more strictly regulated came after Twitter placed a different warning on another of his posts, which fact-checked the claim that mail-in voting would lead to widespread fraud.
Adding the warning is likely to cause yet more animosity between Twitter and Mr Trump, who has ramped up his attacks on the social network since the fact-checking messages were displayed.
It is the first time that Twitter has applied such a warning to the president's tweets. Twitter has said in the past that other potentially violent tweets – such as posts appearing to threaten North Korea with nuclear war – would stay visible on the site becuase they are "newsworthy", despite the fact they would otherwise be judged to have broken the sites rules.
As well as showing a message above the tweet whenever it appears in a users' feed, the decision means that people will not be able to reply or retweet the post.
"We have placed a public interest notice on this Tweet from Donald Trump," Twitter said in a post on its official feed.
"This Tweet violates our policies regarding the glorification of violence based on the historical context of the last line, its connection to violence, and the risk it could inspire similar actions today.
"We've taken action in the interest of preventing others from being inspired to commit violent acts, but have kept the Tweet on Twitter because it is important that the public still be able to see the Tweet given its relevance to ongoing matters of public importance.
"As is standard with this notice, engagements with the Tweet will be limited. People will be able to Retweet with Comment, but will not be able to Like, Reply or Retweet it."
Twitter's thread was retweeted by chief executive Jack Dorsey, who is reported to have been consulted on the plan to add the warning before it happened.
Mr Trump's original post had used the phrase "the shooting starts" and made repeated references to the military, appearing to suggest that protesters could be shot if they continued to protest.
"I can’t stand back & watch this happen to a great American City, Minneapolis. A total lack of leadership. Either the very weak Radical Left Mayor, Jacob Frey, get his act together and bring the City under control, or I will send in the National Guard & get the job done right," he wrote.
"These THUGS are dishonoring the memory of George Floyd, and I won’t let that happen. Just spoke to Governor Tim Walz and told him that the Military is with him all the way. Any difficulty and we will assume control but, when the looting starts, the shooting starts. Thank you!"
Protests first erupted on Tuesday, a day after George Floyd's death in a confrontation with police which was captured on a widely seen video.
On the footage, Mr Floyd can be seen pleading as Officer Derek Chauvin presses his knee against him.
As minutes pass, Mr Floyd slowly stops talking and moving. The 3rd Precinct covers the portion of south Minneapolis where Mr Floyd was arrested.
Minnesota governor Tim Walz earlier activated the US National Guard at the Minneapolis mayor's request, but it was not immediately clear when and where the Guard was being deployed, and none could be seen during protests in Minneapolis or neighbouring St Paul.
The Guard tweeted minutes after the precinct burned that it had activated more than 500 soldiers across the metro area.
The National Guard said a "key objective" was to make sure fire departments could respond to calls, and said in a follow-up tweet it was "here with the Minneapolis Fire Department" to assist.
But no move was made to put out the 3rd Precinct fire. Assistant Fire Chief Bryan Tyner said fire crews could not safely respond to fires at the precinct station and some surrounding buildings.
Earlier on Thursday, dozens of businesses across the Twin Cities boarded up their windows and doors in an effort to prevent looting, with Minneapolis-based Target announcing it was temporarily closing two dozen nearby stores.
Additional reporting by agencies