Donald Trump, presumed Republican nominee for President of the United States, was criticized on Sunday for a tweet he sent out in the aftermath of the Orlando, Florida massacre at a gay nightclub.

“Appreciate the congrats for being right on radical Islamic terrorism, I don’t want congrats, I want toughness & vigilance. We must be smart!” Trump wrote on Twitter about the attack, which left 50 dead and stands as the worst mass shooting in U.S. history. The assailant, Omar Mateen, was a U.S. citizen, born to parents from Afghanistan. He was killed by police in the attack.

Trump’s tweet was roundly denounced online, including by many members of the media and Hollywood community.

Trump didn’t respond to the comments, but did release a statement on the murders, calling for President Barack Obama to step down and Democratic presidential nominee Hillary Clinton to drop out of the race because neither mentioned “radical Islam” in discussing the attack. Trump has previously called for a ban on Muslim men and women from entering America.

“If we do not get tough and smart real fast, we are not going to have a country anymore,” he said in a statement. “Because our leaders are weak, I said this was going to happen – and it is only going to get worse. I am trying to save lives and prevent the next terrorist attack. We can’t afford to be politically correct anymore.”

Clinton also released a statement on the murders, denouncing the attack as an “act of terror” and an “act of hate.”