He made the announcement on Sunday during a speech in Queens, marking his first 100 days in office.
"Grocery shopping will no longer be an unsolvable equation," said Mamdani.
The store is expected to arrive by the end of next year.
"The same market that Fiorello LaGuardia Opened in 1936, so working people then could save money on fruits and vegetables. We will continue his legacy," Mamdani said.
As he continues to try to deliver on affordability promises, Mayor Mamdani made that announcement saying he looks forward to the city stores with lower prices competing with existing ones where prices have gone up 66 percent since COVID.
The mayor also reflected on his first 100 days.
"Not to congratulate ourselves, but as a reminder of what is possible with what we've accomplished in 14 weeks. Imagine what we can do together in four years," he said.
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Using the term 'pothole politics' -- a reference to the ongoing pothole filling blitz.
"Because if the government can't do the small things. How could you ever trust it to do the big ones?" he says.
Supporters here say it's that philosophy that's made him engaging.
"People, if they can see those improvements, see evidence and are more willing to participate, to join in," said supporter Zack Littlejohn.
Most of the people who filled the Knockdown Center in Maspeth were cheering for his policies. Others were looking to hold him accountable going forward.
"As a Jewish New Yorker, I didn't feel like the mayor said anything that makes me feel more securem," said Moshe Spern of United Jewish Teachers.
Crime may be lower, but Spern notes that hate crimes against Jewish New Yorkers need to come down too.
Lauren Phillips, a mom from the Bronx applauded the mayor's 2K plans.
"Next year, of all the questions will be asking, where will we find $26,000 for child care? Will not be one of them," said Phillips.
Education advocates from Harlem hope it really is accessible where it's needed most.
Tanesha Grant/Parents Supporting Parents (a nonprofit)
"We love the idea but we really, really need him to make sure that it's not just till 2 'o'clock and there's after school in place for these kids as well," said Tanesha Grant from the nonprofit 'Parents Supporting Parents.'
"We need more community schools with wraparound services," added Gisele Hearne of Parents Supporting Parents.
Many people in the room were city employees. Sanitation worker Joe Claudio says his department and the mayor seemed to form a good relationship over the massive snow cleanup.
"We feel great about it. He's been very receptive to the needs that we have." said Joe Claudio of Queens.
Another big announcement was what the mayor calls an ambitious trash containerization program, saying it will start with one fully containerized community district in each borough, and declaring that rats will go hungry.
WATCH: 'Mayor Mamdani: First 100 Days': A look at his victories, obstacles and more
'Mayor Mamdani: First 100 Days': An Eyewitness News special presentation
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