NEW YORK: Michael Bloomberg, who spent $1 billion of his own money on a failed 2020 presidential bid, will inject at least $100 million to help Democrat Joe Biden's campaign against President Donald Trump in Florida.

The billionaire's decision comes at a critical moment in the final 51 days of the race, with polls showing a close race in the battleground state and no financial advantage for the sitting president.

Trump's initial financial supremacy over former Vice President Biden has evaporated after the Republican's campaign spent freely and Democratic fundraising surged once the party's divisive primary ended.