The widow of a soldier Donald Trump has accused NFL players of disrespecting has hit back at the US President.

Mr Trump shared a supporter’s tweet on Monday that suggested footballers who kneel during the national anthem were disrespecting the memory of Pat Tillman, a former NFL player who died in Afghanistan after joining the military.

The tweet read: “NFL player Pat Tillman joined US Army in 2002. He was killed in action 2004. He fought 4our country/freedom. #StandForOurAnthem #BoycottNFL”

The President has repeatedly condemned players protesting police brutality before games since first bringing up the issue at a campaign rally in Alabama on 22 September.

The 70-year-old told supporters that any “son of a b****” who decided to kneel should be “fired” by the team’s owner. “That owner, they don't know it [but] they'll be the most popular person in this country,” he added.

Responding to the tweet Mr Trump shared, Mr Tillman’s widow Maria told CNN her husband’s life should “never be politicised in a way that divides us”.

“We are too great of a country for that,” she said. “Those that serve fight for the American ideals of freedom, justice and democracy. They and their families know the cost of that fight. I know the very personal costs in a way I feel acutely every day.

Maria Tillman says her husband's memory should "not be politicised" (Getty Images)

"The very action of self-expression and the freedom to speak from one’s heart — no matter those views — is what Pat and so many other Americans have given their lives for. Even if they didn't always agree with those views.

“It is my sincere hope that our leaders both understand and learn from the lessons of Pat's life and death, and also those of so many other brave Americans."

Mr Trump has appeared increasingly agitated at the prospect of American sports stars continuing to kneel during the national anthem. As well as firing the players, he has suggested audiences boycott games and claimed ratings are “way down”.

The protest movement has been gaining momentum ever since Colin Kaepernick, an NFL quarterback currently without a team, sat down during the national anthem at a pre-season game with the San Francisco 49ers in 2016.

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"I am not going to stand up to show pride in a flag for a country that oppresses black people, and people of colour," Kaepernick said during a press conference after the game.

The 29-year-old later started to take a knee in protest instead, saying he was doing it to show more respect for military veterans.

Over the weekend, some football teams chose to stay off the field completely in protest, while several baseball and basketball professionals have also joined in.

Tillman ended his football career in 2002 to enlist in the US Army in the aftermath of 9/11.