Donald Trump has angrily complained he is being blamed for the far-right terror attack in Christchurch, which has claimed the lives of 50 people.

"The Fake News Media is working overtime to blame me for the horrible attack in New Zealand. They will have to work very hard to prove that one. So Ridiculous!" Mr Trump tweeted on Monday morning.

It comes after the US president was criticised for directing followers on Twitter to Breitbart, a far-right website with a history of anti-Muslim rhetoric, in the hours after the shootings at two mosques in New Zealand last week.

He later extended his "warmest sympathy" and "best wishes" to the "people of New Zealand, but failed to label the shootings a terror attack or criticise the white supremacist ideology behind it - in stark contrast to his rapid response to Islamist terror attacks.

Mr Trump later denied there was a "rising threat" from white nationalism in the wake of the atrocity.

New Zealand shootings: Victims of Christchurch mosque terror attacks Show all 11 1 /11 New Zealand shootings: Victims of Christchurch mosque terror attacks New Zealand shootings: Victims of Christchurch mosque terror attacks Zakaria Bhuiyan People gather hoping to find out information about Zakaria Bhuiyan who is still missing after the mosques shootings in Christchurch. David Moir/AFP New Zealand shootings: Victims of Christchurch mosque terror attacks Mucad Ibrahim Three-year-old Mucad Ibrahim, the youngest known victim of the mass shooting at two mosques in Christchurch, New Zealand, on 15 March 2019. Abdi Ibrahim via AP New Zealand shootings: Victims of Christchurch mosque terror attacks Nadeem Rasheed Nadeem Rasheed, brother of Pakistani Naeem Rashid who died alongside his son Talha Naeem, 21, who were killed in shooting at a Mosque in Christchurch, at their home town in Abbottabad, EPA New Zealand shootings: Victims of Christchurch mosque terror attacks Omar Nabi Omar Nabi speaks to the media about losing his father Haji Daoud Nabi, 71, in the mosque attack REUTERS New Zealand shootings: Victims of Christchurch mosque terror attacks Ash Mohammed Ash Mohammed, right, talks to a police officer about his father and two brothers who are missing near the Masjid Al Noor mosque AP New Zealand shootings: Victims of Christchurch mosque terror attacks Akhtar Khokhur Akhtar Khokhur, 58, shows a picture of her missing husband Mehaboobbhai Khokhar, 65. AP New Zealand shootings: Victims of Christchurch mosque terror attacks Wasseim Alsati A note is seen on a window of a door at the family home of Wasseim Alsati in Christchurch on 17 March 2019. AFP/Getty Images New Zealand shootings: Victims of Christchurch mosque terror attacks Haroon Mahmood Relatives offer condolences to nephew (centre) of Haroon Mahmood, a Pakistani citizen who was killed in Christchurch mosque shootings. AP New Zealand shootings: Victims of Christchurch mosque terror attacks Farid Ahmed Farid Ahmed (pictured) survived the Al Noor mosque shootings but his wife Husne was killed. AFP/Getty Images New Zealand shootings: Victims of Christchurch mosque terror attacks Syed Areeb Ahmed A relative shows a picture of Syed Areeb Ahmed, a Pakistani citizen who was killed the Christchurch mosque shooting. AP New Zealand shootings: Victims of Christchurch mosque terror attacks Naeem Rashid A relative looks at a picture on a mobile phone of Pakistani nationals Naeem Rashid and his son Talha Naeem (right) who died in the Christchurch shootings. AFP/Getty Images

"I think it’s a small group of people that have very, very serious problems," he told reporters at the White House on Friday.

It came despite white supremacist killings in the US more than doubling last year, according to Southern Poverty Law Centre (SPLC), which monitors extremist violence. In a report last month, the organisation accused the president of pushing “noxious anti-immigrant and anti-Muslim ideas into the public consciousness”.

Some commentators have claimed Mr Trump's hostile policies and rhetoric about Muslims has contributed to an emboldening of white supremacism and Islamophobic views.

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.

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.

Christchurch mosque attacks: What we know so far

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.