US President Barack Obama says the US is “not as divided as some have suggested” 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.
The march was against the killing of black men by police. Two deaths this week have led to nationwide protests.
Mr Obama said “it was just not true” the US was returning “to the situation in the 60s”.
His comments, on the side of a Nato summit in Warsaw, echoed those earlier of Vice-President Joe Biden, who said Americans had a duty to stand up against injustice, but that people also needed to support police.
Johnson, who was himself killed during the assault in Dallas, supported black militant groups who encouraged violence against police.
Dallas police chief David Brown said Johnson had told a negotiator that he had wanted to kill white people, especially white police officers, because he was angry about the recent shootings of black men by police.
