Dallas shootings: 'No division' over police deaths
US President Barack Obama denied that there was "enormous polarisation" in the United States, in the wake of fatal shootings involving African-Americans.
Five white police officers were shot dead by a black man, Micah Johnson, during a protest rally on Thursday.
Speaking at a Nato summit in Warsaw, he said the US was not returning to the situation in the 60s, when the civil rights movement arose in response to racial segregation.