Joe Biden is not ruling out running for President in 2020, the former Vice President has said.

"I haven't decided to run," he told Vanity Fair, " but I've decided I'm not going to decide not to run.

"We'll see what happens."

In a separate interview with InStyle Magazine, Mr Biden, who served under Barack Obama, repeated his somewhat confusing take by saying he has not decided to run for president but has also decided he is "not going to decide not to run".

Joe Biden 'we're walking down a dark path'

The 74-year-old Democrat said "this moment in American history sort of fits into my wheelhouse and the strengths I have."

He cited his experience with international diplomacy, his personal authenticity and his willingness to work with both parties.

But he said the decision would be hard on his family, telling Vanity Fair: "You don't run by yourself. Your family is totally implicated. They become news; they become fodder."

Mr Biden said he decided not to run for President in 2016 because of grief caused by the death of his son, Beau, from brain cancer the year before.

"No question," he told the magazine. "I had planned on running, and I wasn't running against Hillary or Bernie or anybody else.

"Honest to God, I thought that I was the best suited for the moment to be President."

Joe Biden and Barack Obama through the years Show all 15 1 /15 Joe Biden and Barack Obama through the years Joe Biden and Barack Obama through the years Joe Biden and Dr Jill Biden watch Barack Obama's farewell speech on 11 January. Obama called Biden his 'brother' Joe Biden and Barack Obama through the years US President Barack Obama speaks alongside US Vice President Joe Biden about the Affordable Care Act AFP/Getty Images Joe Biden and Barack Obama through the years Vice President Joe Biden and President Barack Obama Getty Joe Biden and Barack Obama through the years President Obama listens to Joe Biden speak of his work on defeating cancer on 18 October in the White House Reuters Joe Biden and Barack Obama through the years U.S. President Barack Obama is applauded by House Speaker Paul Ryan and Vice President Joe Biden while delivering his final State of the Union address to a joint session of Congress in Washington Reuters Joe Biden and Barack Obama through the years U.S. Vice President Joe Biden interjects as President Barack Obama delivers remarks at a reception for the 25th anniversary of the White House Initiative on Educational Excellence for Hispanics at the White House in Washington REUTERS Joe Biden and Barack Obama through the years Obama and Vice President Joe Biden react after a heckler was removed for their extended interruption (Reuters) Joe Biden and Barack Obama through the years U.S. President Barack Obama shakes hands with Speaker of the House John Boehner (R) as Vice President Joe Biden looks on Joe Biden and Barack Obama through the years Barack and Michelle Obama and Vice-President Joe Biden observing a moment of silence outside the White House to mark the 13th anniversary of the 9/11 attacks Getty Images Joe Biden and Barack Obama through the years Barack Obama and Joe Biden putt on the White House putting green Getty Joe Biden and Barack Obama through the years President Barack Obama and Joe Biden in April 2013 AFP/Getty Images Joe Biden and Barack Obama through the years January 1, 2013: U.S. President Barack Obama winks as he arrives with Vice President Joe Biden (L) in the briefing room Reuters Joe Biden and Barack Obama through the years President Barack Obama, Vice President Joe Biden and others receive an update on the mission against Osama bin Laden in the Situation Room of the White House May 1, 2011 in Washington, DC Getty Images Joe Biden and Barack Obama through the years Vice-President Joe Biden, right, confirmed that the US was looking at ways of taking legal action against Julian Assange - back in December 2010 GETTY IMAGES Joe Biden and Barack Obama through the years Joe Biden, left, and retired military officers watch President Barack Obama sign orders to close down the detention centre at Guantanamo Bay, Cuba, in January 2009 GETTY IMAGES

He denounced President Donald Trump as not only "self-referential and uninformed" but also a threat to the foundations of America.

“This sounds corny, but everything the founders did was to erect institutions that made it more difficult to abuse power," he said.

"That’s why they have three different branches of government. And what really worries me about this administration is the frontal attack on those institutions that, if they were lost, makes the abuse of power so much more available.”

Explaining his decision not to run for nomination at the last election, Mr Biden said in 2016: “I lost part of my soul when my boy died.