A UN committee charged with tackling racism has issued an “early warning” over conditions in the US and urged the Trump administration to “unequivocally and unconditionally” reject discrimination.

The warning specifically refers to events last week in Charlottesville, Virginia, where civil rights activist Heather Heyer was killed when a car rammed into a group of people protesting against a white nationalist rally.

Such statements are usually issued by the United Nations committee on the elimination of racial discrimination (Cerd) over fears of ethnic or religious conflict. In the past decade, the only other countries issued with an early warning were Burundi, Iraq, Ivory Coast, Kyrgyzstan and Nigeria.

“We are alarmed by the racist demonstrations, with overtly racist slogans, chants and salutes by white nationalists, neo-Nazis, and the Ku Klux Klan, promoting white supremacy and inciting racial discrimination and hatred,” said Anastasia Crickley, chair of the committee.

Donald Trump faced widespread criticism after he blamed “both sides” for the carnage in Charlottesville. Although the Cerd statement did not refer to him by name, it called on “the government of the United States of America, as well as high-level politicians and public officials, to unequivocally and unconditionally reject and condemn racist hate speech and crimes in Charlottesville and throughout the country”.

Crickley had also urged the US authorities “to address the root causes of the proliferation of such racist manifestations”.

The warning was issued on 18 August but came to light on Wednesday, the day after protests outside a rally by the president in Phoenix, Arizona.

Trump used Tuesday’s event to portray himself as the victim of events in Charlottesville, branding journalists who “do not like our country” as the true source of division in America. He also accused the “crooked media” of “trying to take away our history and our heritage” and read out previous statements that he said condemned hatred, bigotry and violence.