WASHINGTON — A day after the deadly terrorist attacks in Spain, President Donald Trump on Friday said radical Islamists “must be stopped by whatever means necessary” and urged U.S. courts to give him the right “to be tough.”

Trump’s tweet appeared to be a reference to lower court rulings on lawsuits that have largely blocked his temporary travel ban affecting travelers from six mostly Muslim countries and will be argued before the U.S. Supreme Court after it returns in October.

“Radical Islamic Terrorism must be stopped by whatever means necessary! The courts must give us back our protective rights. Have to be tough!” Trump tweeted.

It was one of a series of posts to Twitter by Trump before he met with his national security team at the presidential retreat at Camp David in Maryland. Trump was to spend much of the day there before returning to his golf resort in Bedminster, N.J.

Also Friday, Trump faced more criticism for his shifting responses to the clash in Charlottesville, Virginia, between a pro-white group that held a rally to protest the removal of a Gen. Robert E. Lee statue from a park and counterdemonstrators.

Susan Bro, the mother of 32-year-old Heather Heyer who was killed by a car driven into a crowd of counterprotesters, said she would not speak with Trump after the president said “both sides” were to blame for the violence.

Bro said the White House attempted to reach her repeatedly during her daughter’s funeral Wednesday, but she “just missed the calls.” Trump was criticized for not having talked to Bro.

Get the Breaking News newsletter! Get the latest breaking news as it happens. By clicking Sign up, you agree to our privacy policy.

“I’m not talking to the president now,” Bro said Friday on ABC’s “Good Morning America.”

“I’m sorry. After what he said about my child, and it’s not that I saw somebody else’s tweets about him. I saw an actual clip of him at a press conference *equating the protesters like Ms. Heyer with the KKK and the white supremacists,” Bro said.

“You can’t wash this one away by shaking my hand and saying, ‘I’m sorry.’ I’m not forgiving for that,” she said.

James Alex Fields Jr., 20, is charged with second-degree murder in Heyer’s death.

White House press secretary Sarah Huckabee Sanders, responding to Bro’s comments, said, “Our thoughts and prayers continue to be with her and her family.”

Asked on the show if there was something she wanted to say to Trump, Bro said, “Think before you speak.”

Trump did not respond to Bro’s comments.

Instead, Trump focused on terrorism after two vehicle attacks in Spain.

In Barcelona on Thursday, a van drove through pedestrians, killing 13 people and injuring 100 others, and in Cambrils early Friday, an Audi plowed into a crowd, killing one. Spanish police killed five people wearing fake bomb belts who attacked the seaside resort.

Trump reassured his Twitter followers that they are safe.

“Homeland Security and law enforcement are on alert & closely watching for any sign of trouble. Our borders are far tougher than ever before!” Trump tweeted.

Trump also directed that the U.S. Cyber Command be elevated to the status of a unified combatant command focused on cyberspace operations, to improve its defense capabilities, demonstrate an increased effort, reassure allies and partners, and assure adequate funding, according to a White House statement.