Updated at 10:29 p.m.

After months of speculation, Boston City Councilor Michelle Wu announced Tuesday that she is running for mayor against incumbent Marty Walsh.

“Boston should be a city for everyone,” Wu said in an interview with GBH News Tuesday. “We have the resources, the activism, the ideas. We just need bold, urgent leadership. And that has to come from every community in the city.”

Wu says she’s running on a “community-led” platform, specifically focused on improving public education, neighborhood planning, affordable housing, transportation and public health and safety.

“Whether it’s the housing crisis, the opiate crisis, climate vulnerability or transportation access, all of these issues are problems that were already at crisis level before COVID-19, and certainly the pandemic has deepened and exposed just how fragile the status quo was,” Wu said. “But we need to follow the solutions that have already been coming out of the community, lift up leadership from every neighborhood and make sure that we're taking that bold, urgent action that matches the scale and urgency of what our families actually need.”

Wu emphasized the need for a city Green New Deal “for clean air and water, healthy homes, and the brightest future for our children.”

“The climate impacts that Boston faces range from what we see on a regular basis now with flooding during storms that can take out all of Morrissey Boulevard and king tides that flow so that the T stations downtown are unusable for months,” Wu said. “We've been hit by storms. We've been hit by heat. These are all issues that seem like they're, you know, a national or international problem, but in fact, cities can lead the way.”

In 2017, Walsh won reelection by a 2-to-1 margin over challenger Tito Jackson, but his bid for a third term is likely to be much more competitive. Wu may not be the only serious contender in the race: though City Councilor Andrea Campbell has not made any public comment regarding her possible intentions to run, she's been moving money into her campaign, with $285,152 in the bank, according to the state Office of Campaign and Political Finance — a significant amount of money for a city councilor.

Walsh has not yet announced if he will be running for a third term in 2021, and has been floated as a possible Cabinet pick should former Vice President Joe Biden win the presidency in November. Walsh's office sent a statement Tuesday morning saying, "We need to get through COVID-19, save lives, rebuild our economy, broaden equality, further improve our quality of life, and elect Joe Biden and Kamala Harris. That’s my to-do list, and I want to keep everyone in Boston focused on that mission. And when we do, next year and for the next four years, my administration will have a strong partnership with new leadership in the White House. I have great respect for Councilor Wu’s commitment to Boston and I look forward to our conversations about how to move our city forward.”

As a city councilor, Wu has championed issues including paid parental leave, gender equity in health care and access to city resources for non-English speakers and residents with disabilities. In 2018, her office published a climate justice report detailing specific environmental concerns for the city, and in 2017 she authored legislation to increase renewable energy use, limit the use of plastic bags and protect local wetlands.

Wu is a former legal services attorney and a graduate of Harvard Law School. In 2013, she became the first Asian-American woman to serve on Boston City Council, and in 2016, the first woman to serve as council president.

“I’m a mom, a daughter of immigrants, and I’ve lived my whole life knowing what it’s like to feel unseen and unheard, even when you most need help,” Wu said in a campaign video released Tuesday in the three languages she speaks: English, Mandarin and Spanish.

“My parents came to America with no money and no connections, not speaking English. It’s the struggles and dreams of my family and families across our neighborhoods that I’ve carried to city hall the last seven years,” Wu said in the video, against the backdrop of recent Black Lives Matter protests. “Where together, we’ve broken barriers, passed groundbreaking legislation, changed the face of government, and changed the conversation about what is just, and what is possible.”

Wu’s announcement was no surprise; last week, Walsh told the Boston Globe that Wu had called him to notify him of her intentions.

The Chicago native and Roslindale resident has been increasingly critical of Walsh’s policies in recent months, fueling speculation about a possible mayoral campaign. In July, Wu criticized the mayor’s plan to accept funds from donors and corporations to his Boston Resiliency Fund as a “dangerous and deceptive tactic” in an interview with GBH News. Wu has also challenged the mayor on issues concerning affordable housing, and a possible 2024 Olympics bid that she believed would hurt the city’s economy.

When asked where Walsh has fallen short, Wu chose a diplomatic response.

“This is about the idea that city government and the city of Boston should be for every single person, as a place where our progress and our future depends on focusing on more than just one individual, whether that person is an elected official or a leader in some other way,” she said. “We need to focus on every single person having a voice and being heard. It's not just possible to reimagine where Boston it's going. It's necessary in this moment of crisis.”

At a campaign event in Brighton Tuesday evening, a GBH News reporter asked Wu what differentiates her from Walsh. She answered that the issues facing the city resonate with her personally.

"I've grown up as someone who knows what it means when government works and when it doesn't work. I can't escape that urgency," Wu said. "It drives every bit of what I do and whose stories I want to lift up and what changes we need to make."

Wu also said that representation is "everything ... especially at the city level.

"Every action that you take or don't take ripples into the opportunities that the next generation will have," she added, citing the City Council's ban on the use of facial recognition technology as an example of local and "groundbreaking" legislative power.

"We have everything we need in Boston to bring about that kind of transformative, systemic change to address the crisis that people were already living with before COVID-19," Wu said. "We have the resources, the activism, the ideas. We are missing vision and political will to act with the urgency that matches our communities' lives."