US President Donald Trump has been criticised for using again the word 'Pocahontas' in reference to the Massachusetts' senator, Elizabeth Warren, during an event to honour Native American veterans.

The ceremony at the White House on Monday (27 November) featured the president describing three veteran Navajo code talkers from the Second World War as "very special people".

Code talkers transmitted messages using codes derived from lesser known native languages which helped the US army to communicate privately in WW2.

"We have a representative in Congress who they say was here a long time ago. They call her Pocahontas. But you know what, I like you," Trump said.

Trump repeatedly called Warren 'Pocahontas' in reference to questions about her heritage that surfaced during her 2012 senate race.

"This was supposed to be an event to honour heroes, people who put it all on the line for our country, who, because of their incredible work, saved the lives of countless Americans and our allies," Warren fired back in an interview with MSNBC.

"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," she added.

Some also noted that Trump made the comment under a portrait of the US's seventh president, Andrew Jackson, who oversaw the forced removal of native tribes during his tenure in office.

The general secretary of the Alliance of Colonial Era Tribes, John Norwood, told NBC News that the remark "smacks of racism," adding that "the reference is using a historic American Indian figure as a derogatory insult and that's insulting to all American Indians".

Warren has faced claims she has native American ancestry although she said that she never sought proof of her heritage and had only been told about it by her parents.