01/14/2013 04:32 pm ET Updated Dec 06, 2017

Miami Mayor Tomas Regalado Joins Mayors Against Illegal Guns Campaign (VIDEO)

A new public service campaign is hitting airwaves on Monday with the aim of curbing gun violence.

But first, Miami mayor Tomás Regalado joined more than 800 other mayors from around the country Monday morning as he demanded new gun control laws at a press conference at city hall.

"I believe that it is important that we send this message," Regalado said during the media blitz organized by Mayors Against Illegal Guns, an organization that has gained more than 400,000 members in the last month, in addition to nearly one million signatures from citizens petitioning for tighter gun laws.

Regalado's announcement came as MAIG released a new ad featuring the relatives of victims of gun violence, all "demanding a plan" from Congress to prevent another Sandy Hook tragedy (See video below). The push comes one month to the day after 20 children and six adults were massacred by gunman Adam Lanza in Newtown, Connecticut.

In the TV spot, which debuted on the Demand A Plan website, families of victims cry "Enough! A line has been crossed with Newtown. Tell the President and Congress that you demand a plan to reduce gun violence."

In Miami, the mayor was flanked by civic and community leaders and Carol Gardner, whose son was wounded by an AK-47 assault rifle in Liberty City last April.

"My son was killed for no reason," said Gardner of her son Herbert. "Even though it may not benefit me now because he's gone, but [maybe] someone else's child."

Among the recommendations Regalado and MAIG are making are mandated criminal background checks for all gun buyers, a ban on high-capacity ammunition clips, and the outlawing of gun trafficking.