Donald Trump's former defence secretary James Mattis has sharply criticised the US President and his response to the ongoing protests in the US.
Mr Mattis accused Mr Trump of trying to divide the US, and suggested that the country is now seeing the consequences of "three years of this deliberate effort".
He was speaking in response to the ongoing large-scale protests across the US, which were sparked by the death of unarmed black man George Floyd in police custody.
On Monday, Mr Trump threatened to deploy the military in response to clashes between protesters and police.
Former military general James Mattis defended the vast majority of protests as being defined by "tens of thousands of people of conscience who are insisting that we live up to our values".
He also sharply warned against the use of the military to curb protests, saying that would create a "false conflict... between the military and civilian society".
Mr Mattis stepped down as defence secretary early last year, after apparent policy clashes with Mr Trump.
In his new statement, initially published in The Atlantic magazine, Mr Mattis said: "When I joined the military, some 50 years ago, I swore an oath to support and defend the Constitution.
"Never did I dream that troops taking that same oath would be ordered under any circumstance to violate the Constitutional rights of their fellow citizens - much less to provide a bizarre photo op for the elected commander-in-chief, with military leadership standing alongside."
Mr Mattis suggested that society can 'unite without' the US President, stating: "Donald Trump is the first president in my lifetime who does not try to unite the American people - does not even pretend to try. Instead he tries to divide us.
"We are witnessing the consequences of three years of this deliberate effort. We are witnessing the consequences of three years without mature leadership."
Mr Trump took to Twitter to criticise Mr Mattis as the "world's most overrated general".
He claimed: "His primary strength was not military, but rather personal public relations. I gave him a new life, things to do, and battles to win, but he seldom 'brought home the bacon'.
"I didn’t like his 'leadership' style or much else about him, and many others agree."
It comes as US prosecutors said a Minneapolis police officer who was sacked following the death of George Floyd will now face more serious charges.
Derek Chauvin is now accused of second-degree murder (which includes a level of intention), having previously been charged with third-degree murder.
Three other former officers - all of whom were also fired following Mr Floyd's death - have also been charged with aiding and abetting murder.
