New York City Mayor Bill de Blasio officially launched his bid for the presidency on Thursday in a YouTube video, becoming the 23rd candidate to run for the Democratic Party's 2020 nomination.

In the video, de Blasio highlighted income inequality and climate change, pledging to fight both should he be elected president.

"Doesn’t matter if you live in a city or a rural area, a big state, a small state, doesn’t matter what your ethnicity is," de Blasio said. "People in every part of this country feel stuck or even like they’re going backwards. But the rich got richer. I’m a New Yorker, I’ve known Trump’s a bully for a long time. This is not news to me or anyone else here. And I know how to take him on."

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De Blasio framed his agenda as "working families first."

"As president, I will take on the wealthy, I will take on the big corporations," de Blasio said. "I will not rest until this government serves working people. As mayor of the largest city in America, I’ve done just that.

"Donald Trump must be stopped," he added.

"I’m Bill de Blasio, and I’m running for president because it’s time we put working people first," he concluded his announcement video.

As NBC News reported Wednesday, de Blasio is set to travel to Iowa and South Carolina after his announcement for four days of campaigning.

Appearing on ABC News' "Good Morning America" on Thursday alongside his wife, Chirlane McCray, de Blasio said he is running because "working Americans deserve better."

De Blasio was greeted by a group of protesters outside the ABC News studio before his interview. De Blasio told "GMA" host George Stephanopoulos that the protesters provided him with "a little serenading."

Stephanopoulos noted that recent polling showed a vast majority of New Yorkers did not want de Blasio to run for president, to which de Blasio, noting his two electoral victories in New York City, said the only "poll that actually matters is the election."

On Trump, de Blasio said the president "is playing a big con on America."

"I call him 'Con Don,' " de Blasio said, adding that Trump is "trying to convince working Americans he's on their side. It's been a lie from Day One."

Shortly after de Blasio appeared on "GMA," Trump offered up his thoughts on the candidate's presidential bid.

"The Dems are getting another beauty to join their group," Trump tweeted. "Bill de Blasio of NYC, considered the worst mayor in the U.S., will supposedly be making an announcement for president today. He is a JOKE, but if you like high taxes & crime, he’s your man. NYC HATES HIM!"

Some of what de Blasio plans to run on is his liberal record as mayor, which includes enacting universal pre-kindergarten and raising the minimum wage to $15 an hour.

De Blasio will be in a battle to make it onto the debate stage next month, as only 20 candidates will be able to participate. The June 26-27 debates are being hosted by NBC News, MSNBC and Telemundo.

De Blasio, who has served as mayor since 2014 and is in his second term, managed Hillary Clinton's Senate campaign in 2000. The mayor was sworn in by former President Bill Clinton at the start of his first term while Sen. Bernie Sanders, I-Vt., now a presidential rival, swore de Blasio in at the start of his second term.