US President Donald Trump not only used the slur "Pocahontas" at a ceremony honouring Navajo war heroes but did so in front of a portrait of former President Andrew Jackson, who was responsible for the deaths of thousands of Native Americans on the "Trail of Tears".

Mr Trump was speaking during a ceremony honouring the Navajo “code talkers,” Second World War American soldiers who passed sensitive messages in their mother tongue to evade spies and interceptions.

Mr Jackson signed the Indian Removal Act into law in 1830, which led to the forced evacuation of more than 120,000 Native Americans from Georgia, Tennessee, Alabama, North Carolina, and Florida to various points west of the Mississippi River.

It ultimately resulted in the death of at least 4,000 people from the Cherokee tribe, but the Chickasaw, Choctaw, Creek, and Seminole tribes were also devastated on what became known as the “Trail of Tears.”

Most died from the cold, lack of food, or disease on their way to the newly-designated “Indian territory.”

The purpose of the act was to clear the way for cotton growers in those southern states.

Opponents of the bill included Abraham Lincoln, who would go on to become president some 30 years later and fight a bloody Civil War with the South over the issues of secession and slavery.

Mr Trump has a portrait of Mr Jackson - who is also pictured on the $20 bill - hanging in the Oval Office, near his desk.

During the short speech, Mr Trump acknowledged that the Navajo tribe “long before any of us were here”.

But quickly said: “although we have a representative in Congress who they say was here a long time ago. They call her Pocahontas,” using the racial slur to refer to Senator Elizabeth Warren.

He then turned to one of the veterans and put his hand on the man’s shoulder saying: "But you know what, I like you. You are special people."

Since the 2016 campaign during which Ms Warren was a fierce supporter of Hillary Clinton, Mr Trump has repeatedly criticized Ms Warren for saying she has Native American blood; that he doubts her claims about her heritage.

As recently as 3 November, Mr Trump tweeted that “Pocahontas just stated that the Democrats...rigged the Primaries!”

Everyone at the ceremony, including the war heroes, remained silent after Mr Trump’s so-called joke.

Ms Warren told MSNBC after the event: "It is deeply unfortunate that the President of the United States cannot even make it through a ceremony honouring these heroes without having to throw out a racial slur.”