US Senator Bernie Sanders has recorded a video announcing a 2020 run for president, Politico reported Friday, an indication that he plans to enter the already crowded field of candidates.

But it still remains unclear when or if the video will be released, according to Politico, which previously reported that the senator from Vermont's team has been conducting interviews to fill top staff positions.

Sanders, a 77-year-old independent who caucuses with Democrats, made an unsuccessful bid for the presidency in 2016, losing out to Hillary Clinton, who was in turn defeated by Donald Trump.

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Like Trump, Sanders was an outsider when the 2016 presidential primaries began, but came close to pulling off an upset over Clinton.

He garnered passionate support among young liberals with his calls for universal health care, a $15 minimum wage and free public university education.

AP

Sanders served in the House until 2006 when he was elected to the US Senate. He was re-elected in 2012 and 2018.

While Sanders remains popular among many Democrats, some in the party have questioned whether their champion this time around should be a septuagenarian white man.