PORTLAND — Portland Mayor Michael Brennan added his voice to the calls for tighter gun laws in response to the school shootings in Newtown, Conn., last Friday.

Brennan, a former Democratic legislator and Portland’s first popularly elected mayor in decades, announced Thursday that he has signed an open letter from dozens of American mayors “calling on President Barack Obama and members of the U.S. Congress to pursue sensible gun laws.”

Other signers include the mayors of New York, Chicago and Los Angeles, he said. The letter calls for regulations such as a ban on assault weapons and other high-capacity magazines and a stronger national background check system.

“My heart goes out to the community of Newtown,” Brennan said in a written statement. “The burden of grief may seem impossible to bear for the families of Sandy Hook and I hope that as we as a nation come together to share in their grief of this unfathomable loss, we are able to lift some small piece of the load off their shoulders…. I am encouraged by President Obama’s commitment to addressing gun violence and hope that Maine’s Congressional Delegation joins him in this effort. The simple fact of the matter is that reasonable laws and regulations can make a difference in our effort to reduce gun violence.”