Former US vice president Joe Biden has stoked speculation he may run for the White House in 2020 by saying he believes he is the "most qualified person" to be president.
Biden, 76, made the remarks on Monday night while in Montana during a stop on a tour to promote his 2017 book "Promise Me, Dad" about the death from brain cancer of his son Beau.
"I think I'm the most qualified person in the country to be president," a local newspaper, the Missoula Current, quoted Biden as saying.
"The issues that we face as a country today are the issues that I've worked on my whole life – the plight of the middle class and foreign policy," he said.
Biden, who served for eight years as vice president to Democrat Barack Obama, said he would have to consult with his family before deciding whether to take on Republican Donald Trump two years from now.
"My family and I need to decide as a unit whether we're ready - we do everything as a family," Biden said, adding that he would make a decision in the next six weeks to two months.
Joe Biden enjoyed a close relationship with Barack Obama. Source: AAP
Biden, who served as a US senator from Delaware before becoming vice president, was asked whether his reputation for making "gaffes" could harm his prospects.
"I may be a gaffe machine, but my god, what a wonderful thing compared to a guy who can't tell the truth," he said in a reference to Trump.
"No one doubts what I say, the problem is I sometimes say all that I mean," Biden said. "The question is what kind of nation are we becoming?
"We can't have four more years."
Biden, should he decide to run, would be considered a strong candidate in what could be a crowded field seeking the 2020 Democratic nomination for president.
