President Barack Obama early Friday called the attack in Dallas that killed five police officers “vicious, calculated and despicable,” and promised city leaders the full resources of the federal government to ensure “justice will be done.”  

The goal of securing tighter limits on access to firearms , especially the kind of guns designed for combat, has proved elusive for Obama, as congressional Republicans have blocked many Democrat-pushed bills to that end. He did not overtly call for gun control legislation in two statements Friday, but in the second he did say more mass shootings are likely as long as Americans have access to “powerful weapons.”  

Following the June 12 nightclub mass shooting in Orlando, Florida, White House Press Secretary Josh Earnest described Obama as “profoundly frustrated” that Republicans answered by blocking gun control measures in Congress. Earnest also accused GOP members of being “scared of the NRA .” Experts say Republican lawmakers often worry the National Rifle Association, the country’s most powerful pro-gun group, will retaliate by supporting primary opponents with loads of campaign donations.  

Obama, speaking from a NATO summit in Warsaw, Poland, said he had spoken with Dallas Mayor Mike Rawlings to offer his “deepest condolences” after 12 police officers were shot during downtown protests.

It has been a devastating night. We are sad to report a fifth officer has died.

— Dallas Police Depart (@DallasPD) July 8, 2016

The president, speaking yet again about a mass murder involving firearms, stressed that “we don’t know all the facts” surrounding the suspects or the attack, but he said they had “twisted motivations.” Obama vowed that the shooters would be “held fully accountable.” Three suspects reportedly are in custody, and another was reported dead after a standoff with police.  

Obama said there is “no justification” for what he described as “senseless murders,” and urged Americans to express their gratitude for the “hard job” that law enforcement officers do every day across the country.  

He paid homage to the slain Dallas officers, saying they were merely “doing their jobs keeping people safe during peaceful protests.”

Data compiled by the National Law Enforcement Officers Memorial Fund indicated Thursday night’s attack was the deadliest incident for police officers since 9/11, and likely the worst mass shooting of officers in American history.  

Crowds had gathered in the city to protest two recent shootings by police officers in Minnesota and Louisiana.  

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Lawmakers: Dallas Shootings Raise Concerns About Retaliation Against Police

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Philando Castile, 32, was shot and killed Wednesday evening by police in Falcon Heights, Minnesota. His girlfriend, Lavisha Reynolds, streamed the aftermath of the incident live on Facebook.  

And Alton Sterling , 37, was killed by police outside a Baton Rouge convenience store on Tuesday. Louisiana Rep. Cedric L. Richmond called for a Justice Department inquiry into that shooting and an FBI spokesman later confirmed that an investigation was underway.  

In a statement delivered earlier Friday upon landing in Warsaw, Obama addressed those shootings, saying, “We have seen tragedies like this too many times.”  

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Gun Compromise Faces Challenges From Right and Left

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The Minnesota and Louisiana shootings have stoked racial tensions anew across the country. Obama addressed that in his first statement, citing statistics that show African-Americans are 30 percent more likely than whites to be pulled over, and twice as likely to be shot by law enforcement.  

“So when people say, ‘Black Lives Matter ,’ that doesn’t mean blue lives don’t matter; it just means all lives matter, but right now the big concern is the fact that the data shows black folks are more vulnerable to these kinds of incidents,” Obama said.  

“This isn’t a matter of us comparing the value of lives,” Obama said. “This is recognizing that there is a particular burden that is being placed on a group of our fellow citizens. And we should care about that. We can’t dismiss it. We can’t dismiss it.”  

Contact Bennett at johnbennett@cqrollcall.com. Follow him on Twitter @BennettJohnT.