US President Donald Trump after being sworn in as the 45th president of the United States in Washington, DC on 20 January Reuters/Kevin Lamarque

US President Donald Trump promised to review voting procedures following an investigation into already debunked voter fraud.

"I will be asking for a major investigation into voter fraud, including those registered to vote in two states, those who are illegal and even those registered to vote who are dead (and many for a long time). Depending on results, we will strengthen up voting procedures!" Trump wrote in a series of tweets. A few minutes later, the president said he would be making his Supreme Court pick on 3 February.

The pledge comes after weeks of Trump insisting voting fraud cost him the popular vote in the presidential election.

While Trump won 304 electoral colleges, his rival Hillary Clinton won 2,864,974 million more preferences in the popular vote.

Trump claimed on 27 November that he lost the popular vote due to "the millions of people who voted illegally" in the US. These claims were found to be definitively baseless and untrue in multiple fact-checking exercises.

Despite this – and therein supporting Trump's claims – White House press secretary Sean Spicer recently reopened the conversation by citing previously debunked research.

The Trump administration's repetition of false claims has led a Trump commentator, and supporter, to declare the death of objective facts. "There's no such thing, unfortunately, any more as facts. And so Mr Trump's tweet among a certain crowd, a large – a large part of the population, are truth," Scottie Nell Hughes said on panel on NPR's The Diane Rehm Show.

But fellow panellist Glenn Thrush, from Politico, labelled it "an absolutely outrageous assertion". He said: "Of course there are facts. There is no widespread proof that three million people voted illegally. It's been checked over and over again. We had a Pew study that took place over 15 years that showed people had more likelihood of being struck by lightning than voting illegally in an election."

Popular Vote