Former President Barack Obama delivered a lengthy response to the dual mass shootings that killed 31 people in Texas and Ohio over the weekend. He blamed guns, white supremacist websites, and President Donald Trump’s rhetoric for the ongoing violence in the United States.

In a message shared on Twitter, the former president specifically called for more gun control to help prevent more mass shootings.

“Until all of us stand up and insist on holding public officials accountable for changing our gun laws, these tragedies will keep happening,” Obama said in a statement, citing “evidence” that proved that more gun control could stop “some killings.”

Obama lamented that “no other nation on Earth” experienced the level of gun violence the United States does.

The former president also called for more censorship of “white nationalist websites” to prevent radicalization.

“[T]here are indications that the El Paso shooting follows a dangerous trend: troubled individuals who embrace racist ideologies and see themselves obligated to act violently to preserve white supremacy,” he wrote.

He compared the radicalization of white nationalists to that of followers of Islamic State (ISIS) terrorists.

“That means that both law enforcement agencies and internet platforms need to come up with better strategies to reduce the influence of these hate groups,” he wrote.

While Obama did not cite President Trump’s rhetoric specifically, he called Americans to “soundly reject language coming out of the mouths of any of our leaders that feeds a climate of fear and hatred or normalizes racist sentiments.”

He also criticized rhetoric meant to “demonize those who don’t look like us” or suggest that immigrants were “sub-human” or threatened the American way of life.

Obama indicated that rhetoric, such as the kind Trump voiced, was the root of the worst moments in human history — citing Jim Crow laws, the Holocaust, Rwanda Genocide, and ethnic cleansing in the Balkans.

“It has no place in our politics and our public life,” he wrote. “And it’s time for the overwhelming majority of Americans of goodwill, of every race and faith and political party, to say as much — clearly and unequivocally.”

The president also shared a link to a Vox.com article calling for a bold plan to enact gun control: