Rep. Ilhan Omar has said she has received an increase in death threats after US President Donald Trump posted a tweet reading "We will never forget!", accompanied by video footage of 9/11 and the congresswoman's remark.

"Since the president's tweet Friday evening, I have experienced an increase in direct threats on my life — many directly referencing or replying to the President's video," Omar said in a statement.

"Violent rhetoric and all forms of hate speech have no place in our society, much less from our country's Commander in Chief," she added. "We are all Americans. This is endangering lives. It has to stop." 

Speaker of the United States House of Representatives Nancy Pelosi said that she had spoken with the House's sergeant-at-arms to confirm that Capitol Police conduct a security assessment for Ilhan Omar and her family.

Omar made a scandalous statement about the 9/11 terrorist act during her speech at a meeting with human rights organisations, which took place in late March.

On 11 September 2001, two planes rammed the World Trade Center's twin skyscrapers, while another one rammed a wing of Department of Defense's Pentagon building. A fourth plane crashed near Shanksville, Pennsylvania. The total death toll of the attacks is estimated at 2,996 people.

Following the attack, the administration of US President George W Bush introduced a number of measures, including creating the Department of Homeland Security and introducing the PATRIOT Act, which took away some US citizens' liberties in exchange for heightened security.