Turkey's Erdogan slams US police killing as 'fascist'
Erdogan's comments are likely to irritate Turkey's NATO ally, with relations between the two countries already strained over Turkey's acquisition of the S-400 missile system from Russia.
George Floyd died on Monday night after being arrested on suspicion of using a counterfeit banknote. A video of the incident showed an officer kneeling on his neck as he was pinned to the ground saying "I can't breathe".
Floyd, thought to be in his 40s, slowly lost consciousness and was unable to move even as the officers taunted him to "get up and get in the car".
He was taken to hospital where he was later declared dead.
Rioting has broken out in several US cities over this incident and several others where police have killed African-Americans.
"The racist and fascist approach that led to the death of George Floyd in the US city of Minneapolis as a result of torture has not only deeply saddened all of us, but it has also become one of the most painful manifestations of the unjust order we stand against across the world," Erdogan tweeted in English.
"Turkey always stands against all attacks targeting humanity, no matter where, under what pretext or in what form they are committed," said Erdogan.
"We will continue to fight to protect the rights of all of humanity without any discrimination based on race, color, religion, language or faith," he added.
The Turkish president also quoted a saying of the Prophet Muhammad: "A white has no superiority over a black, nor a black has any superiority over a white."
"I believe that the perpetrators of this inhumane act shall receive the punishment they deserve. We will be monitoring the issue," he said.
"I remember with respect George Floyd and extend my condolences to his family and loved ones."
However, President Erdogan has also recently faced criticism over his human rights record.
Turkey has seen a wide-ranging crackdown on government critics and human rights activists, especially since an attempted coup against Erdogan in 2016.
Tens of thousands were jailed and more than 100,000 people lost their jobs under the two-year state of emergency that followed the failed coup.
There has also been an increase in racism against Syrian refugees in recent years, with hundreds being arbitrarily rounded up and deported to war-torn Syria by Turkish authorities.