Mark Brzezinski refuted Donald Trump’s claim that the Scandinavian nation has experienced rising crime rates since accepting hundreds of thousands of refugees, and emphasised that an attack the President alluded to had never happened.

“I can report to you that the most nefarious thing that happened in Sweden this past weekend was technical difficulties at the Melfest music festival,” he told MSNBC news.

“Nothing more serious than that.”

Mr Brzezinski said in the interview that, far from proving Mr Trump’s point that immigrants were dangerous, Sweden proves the opposite: that immigration can be extremely beneficial to a country.

“Take a look at the economy, Sweden’s economy is booming,” he said. “Skype, Spotify, Minecraft… the tech industry is doing extremely well.”

Sweden, which has a population of under 10 million, has taken in hundreds of thousands of refugees from Syria, Somalia and Yemen in the last couple of years, Mr Brzezinski said, adding "they see themselves as something of a humanitarian super power".

"Yes its been expensive and difficult at times to help move forward the assimilation, but they are absolutely committed to it and that has benefited the country,” he said.

To undermine the "generosity" of the Swede's in helping so many asylum seekers is a bad idea for America, he said.

“In certain ways they are providing an international service through their generosity by letting a lot of people come in," he said, pointing out that Sweden was not the first country most refugees reach, it is just one of the most welcoming.

Mr Brzezinski went on to describe Mr Trump's comments at a Florida rally, which alluded to sinister things that had allegedly happened "last night" in Sweden, as "befuddling".

The US President later admitted he was talking about a widely debunked Fox News report he had seen on television the night before.

But he refused to retract his point, tweeting on Monday: “Give the public a break – The FAKE NEWS media is trying to say that large scale immigration in Sweden is working out just beautifully. NOT!”

Mr Brzezinski, who worked for the National Security Council before becoming an ambassador, said Mr Trump’s behaviour in apparently ignoring his advisers and pushing ahead with "improvised" policy was “sinister”.

“It does seem that he is building a narrative on an improvisational basis based on what he sees on cable news and news reports. That is a dangerous thing to do” he said.

“Secondly it doesn’t seem that he is relying on the national security process in the White House. If there had been a terrorist attack in Sweden, one of our closest partners, the president would have been briefed on it by his national security team.”

He added: “When it comes to things as serious as immigration and terrorism you have to be absolutely factually accurate."

There is a process in place to help the president keep up to date, he said. “No one person can do it on their own. There is simply too much happening and too fast to build policy on an improvisational basis.”

He added that if his facts had been checked, Mr Trump would have found out that the crime rate in Sweden has actually been relatively constant over the last three years, despite an increasing population, and there has been no major "uptick" in the last decade.

“The largest uptick, according to the State Department's crime reports is in computer fraud in a place like Sweden,” he said, dismissing Mr Trump's talk of violent crime.

People strike across America for A Day Without Immigrants Show all 16 1 /16 People strike across America for A Day Without Immigrants People strike across America for A Day Without Immigrants Demonstrators march during the "Day Without Immigrants" protest in Chicago, Illinois, February 16, 2017. Theopolis Waters/Reuters People strike across America for A Day Without Immigrants Demonstrators march during the "Day Without Immigrants" protest in Washington, DC, U.S., February 16, 2017. Aaron P. Bernstein/Reuters People strike across America for A Day Without Immigrants Protesters march in the streets outside the Texas State Capital on 'A Day Without Immigrants' February 16, 2017 in Austin, Texas. The crowd, which grew to well over a thousand participants, marched from the Austin City Hall to the Texas State Capital. Across the country hundreds of restaurants and eateries are closing for the day to protest President Trump's immigration policies and to highlight the contributions of immigrants to U.S. business and life. Drew Anthony Smith/Getty People strike across America for A Day Without Immigrants Protesters march in the streets outside the Texas State Capital on 'A Day Without Immigrants' February 16, 2017 in Austin, Texas. Drew Anthony Smith/Getty People strike across America for A Day Without Immigrants AUSTIN, TX - FEBRUARY 16: Protesters march in the streets outside the Texas State Capital on 'A Day Without Immigrants' February 16, 2017 in Austin, Texas. Drew Anthony Smith/Getty People strike across America for A Day Without Immigrants Demonstrators march during the "Day Without Immigrants" protest in Chicago, Illinois, February 16, 2017. Theopolis Waters/Reuters People strike across America for A Day Without Immigrants Demonstrators march during the "Day Without Immigrants" protest in Chicago, Illinois, February 16, 2017. Aaron P. Bernstein/Reuters People strike across America for A Day Without Immigrants Protesters march in the streets outside the Texas State Capital on 'A Day Without Immigrants' February 16, 2017 in Austin, Texas. The crowd, which grew to well over a thousand participants, marched from the Austin City Hall to the Texas State Capital. Across the country hundreds of restaurants and eateries are closing for the day to protest President Trump's immigration policies and to highlight the contributions of immigrants to U.S. business and life. Drew Anthony Smith/Getty People strike across America for A Day Without Immigrants Protesters march in the streets outside the Texas State Capital on 'A Day Without Immigrants' February 16, 2017 in Austin, Texas. Drew Anthony Smith/Getty People strike across America for A Day Without Immigrants Protesters march in the streets outside the Texas State Capital on 'A Day Without Immigrants' February 16, 2017 in Austin, Texas. Drew Anthony Smith/Getty People strike across America for A Day Without Immigrants Protesters march in the streets outside the Texas State Capital on 'A Day Without Immigrants' February 16, 2017 in Austin, Texas. Drew Anthony Smith/Getty People strike across America for A Day Without Immigrants Protesters march in the streets outside the Texas State Capital on 'A Day Without Immigrants' February 16, 2017 in Austin, Texas. Drew Anthony Smith/Getty People strike across America for A Day Without Immigrants Protesters march in the streets outside the Texas State Capital on 'A Day Without Immigrants' February 16, 2017 in Austin, Texas. Drew Anthony Smith/Getty People strike across America for A Day Without Immigrants Protesters march in the streets outside the Texas State Capital on 'A Day Without Immigrants' February 16, 2017 in Austin, Texas. The crowd, which grew to well over a thousand participants marched from the Austin City Hall to the Texas State Capital. Across the country hundreds of restaurants and eateries are closing for the day to protest President Trump's immigration policies and to highlight the contributions of immigrants to U.S. business and life. Drew Anthony Smith/Getty People strike across America for A Day Without Immigrants High school student Kathia Suarez holds up a sign as she protests with others outside the Grayson County courthouse in downtown Sherman, Texas, Thursday, Feb. 16, 2017. LM Otero/AP People strike across America for A Day Without Immigrants High school senior Vicky Sosa holds a sign outside the Grayson County courthouse in downtown Sherman, Texas, Thursday, Feb. 16, 2017. In an action called "A Day Without Immigrants," immigrants across the country are expected to stay home from school, work and close businesses to show how critical they are to the U.S. economy and way of life. LM Otero/AP

Mr Trump said his speech had been informed by a segment on a Fox News broadcast on Friday night by Tucker Carlson. Mr Carlson interviewed Ami Horowitz, producer of a film that claimed to document alleged violence committed by refugees in Sweden.

News of Mr Horowitz’s documentary made headlines last year when he told conservative outlets such as Breitbart News that there were Muslim “no-go zones” in Europe.