Speaking to journalists following the shootings in Christchurch, the US president claimed white supremacists were “a small group of people that have very, very serious problems”.
The massacre on Friday has sparked renewed warnings about the growing threat of neo-Nazism, and followed deadly far right attacks in the the US, the UK and elsewhere in Europe in recent years.
Asked by a reporter on Friday if he saw “white nationalism as a rising threat around the world”, Mr Trump replied: “I don’t really. I think it’s a small group of people that have very, very serious problems.
“I guess, if you look at what happened in New Zealand, perhaps that’s a case. I don’t know enough about it yet. They are just learning about the person and the people involved. But it’s certainly a terrible thing.”
The suspect charged over the Christchurch attack is believed to have links with violent racist groups in Europe and Asia. Brenton Tarrant is thought to have met with extreme right-wing organisations in Europe two years ago, according to security sources.
In a self-styled “manifesto” published online, the 28-year-old said he had been inspired by white supremacist terrorist Anders Breivik, who killed 77 people in Norway in 2011. He also referenced Dylann Roof, who shot dead nine black churchgoers in Charleston, South Carolina, in 2015 in a purported attempt to start a race war.
Elsewhere in the 74-page document, Tarrant praised Mr Trump as “symbol of renewed white identity and common purpose”.
White supremacist killings in the US more than doubled last year, according to Southern Poverty Law Centre (SPLC), which monitors extremist violence. In a report in last month, the organisation accused the president of pushing “noxious anti-immigrant and anti-Muslim ideas into the public consciousness”.
New Zealand's prime minister, Jacinda Ardern, said on Saturday she did not agree with Mr Trump's assessment that white supremacism did not pose a growing threat.
She added she had spoken to the US president and asked him to show "sympathy and love for all Muslim communities". Mr Trump "acknowledged that and agreed", she said.
The president has repeatedly been accused of emboldening the far right during his time in the White House.
On Friday, during the same press conference in which he downplayed the rise of white supremacism, he depicted immigration to the US as an "invasion". The remark came as he sought to justify declaring a national emergency to secure funds for a US-Mexico border wall.
During his campaign for the presidency, Mr Trump called for a "total and complete shutdown" of Muslims entering the US and told supporters he would look at ways to "get rid of them" from the country.
In 2017, after an anti-fascist activist was killed at a white supremacist rally in Charlottesville, he refused to condemn far right violence and said there were "very fine people on both sides".