US President Donald Trump’s “silence” on the rise of white supremacy was condemned Sunday by Democrats led by an Arab-American lawmaker as the New Zealand mosque massacre generated a heated debate over religious and racial bigotry.

Facing pressure over Trump’s lukewarm response to the massacre, White House chief of staff Mick Mulvaney was forced to deny there was a connection between the president’s anti-immigration rhetoric and the accused Christchurch shooter’s extremist views.

“The president is not a white supremacist,” Mulvaney said in an interview with Fox News Sunday.

But on a separate Sunday talk show, Rashida Tlaib, a Democrat from Detroit and one of the first two Muslim women ever elected to the US Congress, claimed that Trump’s refusal to speak out forcefully against white supremacy was endangering the country.

“Trump is the most powerful man in the world right now,” she said on CNN’s State of the Union. “He, from the Oval Office, from that power position, can be able to send a signal very loud and clear.”

Se added, “We’ve done this in the past against foreign terrorism. We need to do it on domestic terrorism, against white supremacy that’s growing every single day that we stay silent.”

After the attack on two mosques in Christchurch on Friday, which left 50 dead, Trump expressed sympathy and solidarity with the victims and people of New Zealand.

However, in comments to reporters in the Oval Office, he dismissed concerns that white nationalism represented a growing threat to global security.

“I don’t really. I think it’s a small group of people that have very, very serious problems, I guess,” Trump said.

– with reporting by Agence France-Presse