Attorney General Loretta Lynch called Thursday night's attack on Dallas police officers an unfathomable tragedy, stressing the bloodshed of the past week mustn't become the "new normal."
"After the events of this week across our country, many are feeling a sense of helplessness, uncertainty and fear. These feelings are understandable, and they are just, but the answer must not be violence," Lynch said Friday in an address to the media, also mentioning this week's officer-involved shootings in Minnesota and Louisiana.
"I ask you, I implore you, do not let this week precipitate a new normal in this country."
Five police officers were killed and seven were wounded by sniper fire Thursday night in an "ambush-style" attack in Dallas.
The killings took place during a protest against the use of deadly force by police against African-Americans and immediately fueled an already divisive national debate. The attacks follow shootings by police in Minnesota and Louisiana of black men, both caught on camera and both spurring protests.
The demonstrations in Dallas were sparked by those killings.
Lynch encouraged members of the Black Lives Matter movement to keep letting their voices be heard, vowing their rights to free speech would be protected.
"Your voice is important. Do not be discouraged by those who will use your lawful activities as a cover for their heinous violence," Lynch said.
Lynch also called for better relationships between communities and law enforcement and said the U.S. must "guarantee everyone equal justice under the law."
"We must reflect on the kind of country we want to build, and the kind of society we are choosing to pass on to our children," Lynch said.
President Obama also condemned the shootings as a despicable act in a statement from a NATO summit in Warsaw, Poland.
"I believe I speak for every single American when I say we are horrified over these events, and we stand united with the people and the police department in Dallas,” Obama said.
"Anyone involved in the senseless murders will be held fully accountable. Justice will be done."