'Police are furious!': Trump warns de Blasio over Black Lives Matter mural near Trump Tower

Donald Trump warned New York Mayor Bill de Blasio on Thursday over his plan to put a "Black Lives Matter" mural across from Trump Tower in Manhattan, tweeting that the city's police force is "furious."

The president, as he was descending into Green Bay, Wisconsin to tape a Fox News campaign town hall event, fired off two tweets about ongoing protests over perceived racial inquiry and unfair treatment of black people by police officers. One accused those protesting and calling for changes of being guilty of "treason" and other federal crimes.

Mr de Blasio's office says the major intends to install the mural on Fifth Avenue between 56th and 57th streets, which is indeed across from Mr Trump's building where he lived and worked for years.

"Told that @NYCMayor Bill de Blasio wants to paint the fabled & beautiful Fifth Avenue, right in front of Trump Tower/Tiffany, with a big yellow Black Lives Matter sign," he tweeted.

The president then appeared to issue a warning to both the mayor and the protesters, writing: "'Pigs in a Blanket, Fry 'Em Like Bacon', referring to killing Police, is their chant. NYC Police are furious!"

Protesters in some cities have been using that chant, according to media reports and videos posted online.

Meantime, the president escalated his feud with those leading the "Black Lives Matter" movement as he accused them of some of the country's most serious federal crimes, saying they have betrayed their country.

"Black Lives Matter leader states, 'If U.S. doesn't give us what we want, then we will burn down this system and replace it,'" he wrote. "This is Treason, Sedition, Insurrection!"

The president appeared to be reacting to comments made on Thursday by Hawk Newsome, the Black Lives Matter organisation chairman, on Fox News.

"And I could be speaking figuratively," he said. "I could be speaking literally. It's a matter of interpretation."

Mr Trump, trailing former Vice President Joe Biden by double-digits in most national polls, is all too eager to interpret those and other remarks in a way he can try revving up his base. With the presumptive Democratic presidential nominee also leading the president in most key swing states, even if narrowly, political operatives in both parties say he will need a big turnout from that very conservative base to pull off a second win.

For his part, Mr Biden tweeted on Wednesday evening for his supporters to "ignore the polls," with a link to register to vote.

As Mr Trump was taping the town hall in a state he won by less than 1 percentage point in 2016, Mr Biden was talking health care with voters in another key swing state: Pennsylvania.

"I've been a significant consumer of health care myself, my family. I don't think people really fully understand that there's 100 million people with pre-existing conditions ... that if the president wins this case" at the Supreme Court against the Affordable Care Act, "he keeps saying he'll cover pre-existing conditions," Mr Biden said. "But he hasn't figured out any way it's possible to do that absent what we've done."