For the first time in his White House tenure, President Barack Obama handed the weekly address to someone outside his administration.
He stepped aside so a mother who lost her son in the Newtown school massacre could press Congress to act on new measure tightening access to guns.
"As you've probably noticed, I'm not the president. I'm just a citizen. And as a citizen, I'm here at the White House today because I want to make a difference and I hope you will join me," said Francine Wheeler, whose son Ben, 6, was killed at Sandy Hook Elementary School in December.
"I've heard people say that the tidal wave of anguish our country felt on 12/14 has receded," Wheeler continued, referring to the day of the Newtown shooting. "But not for us. 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. Thousands of other families across the United States are also drowning in our grief. Please help us do something before our tragedy becomes your tragedy."
White House spokesman Jay Carney told reporters on Friday that Obama asked Wheeler to tape the address, which is heard on radio and seen on the Internet.
In an email from the White House on Saturday, Obama wrote he takes the address "very seriously because it offers a chance to bring focus to an issue that needs to be part of the national dialogue."
Wheeler and other families who lost loved ones at Sandy Hook have been in Washington this week to lobby Congress for passage of gun legislation that would expand background checks and take other steps designed to curb gun violence.
"We have to convince the Senate to come together and pass commonsense gun responsibility reforms that will make our communities safer and prevent more tragedies like the one we never thought would happen to us," Wheeler said, noting that earlier this week it appeared gun control measures would stall in the Senate.
"Then, after the president spoke in Hartford, and a dozen of us met with senators to share our stories, more than two-thirds of the Senate voted to move forward," she said, referring to Thursday's Senate action that paved the way for debate on new gun laws.
"But that's only the start," she cautioned. "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."
Carney told reporters the president believed the Newtown families in Washington have been "critical to the continued progress we've seen in the Senate."
A senior Obama administration official told CNN Wheeler wrote the remarks with her husband, and taped the address in the library at the White House on Friday morning. The address features only Wheeler and her husband David on camera.
This is the first time someone other than the president or vice president in this administration has delivered the weekly presidential address, Carney said Friday.
CNN found one instance in the George W. Bush administration when first lady Laura Bush delivered the address on the Taliban oppression of women and children in Afghanistan.
President Franklin D. Roosevelt originated the practice of delivering radio addresses on current issues, which was renewed by President Ronald Reagan in the 1980s. All succeeding presidents have followed the tradition.