WASHINGTON, Nov. 24 (Xinhua) -- Former mayor of New York City Michael Bloomberg launched a video ad Sunday to formally announce his campaign for president in the 2020 U.S. election.

The minute-long campaign ad portrayed the 77-year-old media mogul as "jobs creator, leader, problem solver."

The announcer said in the ad that Bloomberg, who runs as a Democrat, will let the wealthy pay more in taxes, the middle class get their fair share and everyone be able to get health insurance.

The ad also highlighted the billionaire's efforts to restore New York after the 9/11 terrorist attacks in 2001, as well as his resolve to tackle climate change.

"I'm running for president to defeat Donald Trump and rebuild America," Bloomberg said in a tweet to which the ad was attached.

"I believe my unique set of experiences in business, government, and philanthropy will enable me to win and lead," he added in the tweet, in which he also provided the link to his campaign website.

Citing advertising analyses, U.S. media reported that the former three-term New York City mayor has spent over 30 million U.S. dollars so far in buying airtime reservations for TV commercials promoting his political agenda across the country, an amount that overshadows the campaign advertising budgets of other Democratic contenders.

Bloomberg filed paperwork earlier this month to join the Democratic primaries in Alabama and Arkansas -- signs that he was preparing for a late entry into the presidential race.

Commenting on his potential rival, Trump told reporters earlier this month he could easily beat Bloomberg. The president said he expected the former mayor of his hometown to "spend a lot of money" on a campaign, while teasing him, saying he "doesn't have the magic to do well."

The owner of Bloomberg News with a net worth estimated by Forbes of 52 billion dollars, Bloomberg considered running for president earlier this year, and eventually gave up the idea reportedly partly due to Democratic candidate and former Vice President Joe Biden's strength.

Moderate Biden has not gained momentum so far as quickly as some Democrats have expected. It is believed to be the main reason compelling Bloomberg to enter the race.

Also a centrist, Bloomberg is perceived as friendlier to business than progressive-leaning Democratic contenders.