President Barack Obama handed over his weekly radio address to the grieving mother of a Newtown massacre victim on Saturday as debate raged over proposed gun control legislation.

In a rare move which ramped up pressure on US lawmakers ahead of debates on gun control in Congress, Francine Wheeler -- whose son Ben was one of 20 children shot dead in Newtown on December 14 -- urged legislators to act.

Wheeler said the pain of families remained as raw as ever, four months after gunman Adam Lanza's rampage through the Sandy Hook Elementary School in Newtown, Connecticut which left 26 children and staff dead.

"I've heard people say that the tidal wave of anguish our country felt on 12/14 has receded. But not for us," Wheeler said.

"To us, it feels as if it happened just yesterday. And in the four months since we lost our loved ones, thousands of other Americans have died at the end of a gun.

"We have to convince the Senate to come together and pass common sense gun responsibility reforms that will make our communities safer and prevent more tragedies like the one we never thought would happen to us."

On Thursday, the US Senate voted to debate the most ambitious gun safety legislation in almost two decades.

Congress is due to vote next week on amendments to a bill that would tighten checks for firearms buyers, stiffen penalties on gun trafficking and boost school safety measures.

Wheeler said that while she was pleased the Senate had moved forward with plans for a vote, much work needed to be done.

"That's only the start. They haven't yet passed any bills that will help keep guns out of the hands of dangerous people. And a lot of people are fighting to make sure they never do," she said.

"Now is the time to act."