In a brief statement to reporters, Obama said the investigation into the shooting continues but “what we do know is there has been a vicious, calculated and despicable attack on law enforcement.”

Obama called the shooters motives “twisted” and vowed that “justice will be done.”

“There’s no possible justification for these kinds of attacks or any violence against law enforcement,” Obama said, noting that he had spoken with Dallas Mayor Mike Rawlings and offered his support and condolences.

Obama spoke from Warsaw, Poland, where he is meeting with NATO and European Union leaders. Obama arrived early Friday shortly before snipers opened fire on police officers, killing five officers and injuring six others during protests over two recent fatal police shootings of black men.

Immediately after landing in Warsaw, and before the shootings, Obama had expressed solidarity with protesters. He has acknowledged becoming out of the touch with the public mood during past foreign travels and seemed determined not to let that happen this week. He aired his frustration with what he said were racial disparities in the criminal justice system.

But he also seemed attuned to the potential for backlash directed at police. He argued that there was no contradiction between supporting law enforcement and working to see that biases in the justice system are rooted out.

Past statements about other shootings have stoked tensions with law enforcement, including with FBI Director James Comey, who has suggested the intense public focus on police officers’ conduct, fueled by caught-on-camera moments could inhibit officers as they try to protect their communities.

Aiming to pre-empt that concern, Obama said that speaking out about the issue is not an attack on police. Obama said that he and other Americans appreciate the risks police officers take.

“And so, to all of law enforcement, I want to be very clear: We know you have a tough job. We mourn those in uniform who are protecting us who lose their lives,” he said prior to the Dallas shootings.

Obama emphasized another part of that message in the aftermath Friday. He called the shootings a “wrenching reminder of the sacrifices” that police officers make every day.

“Police across America, which is a tight-knit family, feel this loss to their core,” Obama said. “And we’re grieving with them.”