Washington: American rapper Kanye West, a vocal supporter of US President Donald Trump, announced on Saturday that he would run for president in 2020 in an apparent challenge to Trump and his presumptive Democratic rival, former Vice President Joe Biden.

The multiple Grammy winner took to social media on country's 244th Independence Day (July 4) to share the news.

"We must now realize the promise of America by trusting God, unifying our vision and building our future. I am running for president of the United States," West wrote in a Twitter post, adding an American flag emoji and the hashtag "#2020VISION".

It was not immediately clear if West was serious about vying for the presidency four months before the November 3 election or if he had filed any official paperwork to appear on state election ballots.

The deadline to add independent candidates to the ballot has not yet passed in many states.

According to NBC, during a speech at the MTV Video Music Awards in 2015, West said he was planning on running for president in 2020.

The recording artiste also opened up about taking a political plunge as recently as November 2019.

"When I run for president in 2024, we would've created so many jobs that I'm not going to run, I'm going to walk," he had said at an event.

At one meeting in October 2018, West delivered a rambling, profanity-laden speech in which he discussed alternative universes and his diagnosis of bipolar disorder, which he said was actually sleep deprivation.

The "Power" hitmaker and his wife, equally famous reality TV star Kim Kardashian West have often visited Trump at the White House in the last few years.

West has also often been spotted wearing the signature Trump campaign 'Make America Great Again' cap.

On his announcement, he received backing from Kardashian, who retweeted his post with an emoji of the American flag.

Elon Musk, the chief executive of electric-car maker Tesla and another celebrity known for eccentric outbursts, also endorsed West's Twitter post: "You have my full support!" he wrote.