CBS News:

President Obama sought to assure Americans that despite the "tough week" for the country, the nation still remains united, contrary to the fears of some that racial tensions -- in the wake of recent deadly shootings -- are boiling over and exposing deep divisions in the United States.

"As painful as this week has been, I firmly believe that America is not as divided as some have suggested," the president said Saturday, in a closing address to the NATO summit in Warsaw, Poland.

Americans of all races and all backgrounds are "rightly outraged by the inexcusable attacks on police," Mr. Obama noted, including protesters and family members who have "grave concerns about police conduct."

"They have said this is unacceptable. There's no division there," he added. Americans of all races and backgrounds are also "rightly saddened" by the deaths of Alton Sterling, Philando Castile and other black civilians at the hands of police system, the president said, along with the "larger persistent problems" of racially discriminatory practices in the criminal justice system.

"There is sorrow, there is anger, there is confusion about next steps, but there is unity in recognizing that this is not how we want our communities to operate," Mr. Obama said. "This is not how we want to be as Americans. And that serves as the basis for us being able to move forward in a constructive and positive way."