US shooting: Our hearts are broken today, says tearful Barack Obama

US President Barack Obama choked up several times as he said "our hearts are broken today" before the White House Press Corps.

Washington: In a rare show of wrenching emotion, US President Barack Obama wiped tears from his face and choked on his words as he spoke to reporters at the White House on Friday in a live televised broadcast after a deadly mass shooting at an elementary school in Connecticut.

"Our hearts are broken today for the parents and grandparents, sisters and brothers of these little children, and for the families of the adults who were lost," Obama said.

"Our hearts are broken for the parents of the survivors, as well, for as blessed as they are to have their children home tonight, they know that their children`s innocence has been torn away from them too early and there are no words that will ease their pain," he added.

"I know there`s not a parent in America who doesn`t feel the same grief that I do," Obama, the father of two daughters aged 11 and 14, said as he stood at the podium in the White House press room, visibly struggling to keep his emotion in check.

"The overwhelming majority of those who died today were children, beautiful little children between five and 10 years old. They had their entire lives ahead of them. Birthdays. Graduations. Weddings. Kids of their own," he said.

Obama paused repeatedly as he spoke and the muscles near his right eye twitched as he worked to maintain his composure.

Authorities said 28 people, including 20 children, died in the shooting at the Sandy Hook Elementary School in the town of Newtown, Connecticut about 100 km northeast of New York City.

It was a brief but extraordinary public show of emotion from a President known for his cool level-headedness amid the daily bombast of Washington politics and who has demonstrated steely stoicism at some of the most gripping moments of his presidency.

Part of any US President`s job description includes a role loosely referred to as "consoler-in-chief", and Obama has generally been sombre and grim in the face of tragedies ranging from visiting sites of natural disasters to greeting the caskets and the families of slain US soldiers.

In his White House appearance on Friday, the resolutely secular Obama cited scripture, mentioned praying for the victims and admitted that his reaction was coloured as much by his vocation as a father as it was by his duty as the President.

Friday`s massacre was the second public shooting rampage in the US this week alone, one of the deadliest in recent memory and the latest such incident in a string of mass shootings in the United States this year.

"As a country, we have been through this too many times, whether it`s an elementary school in Newtown or a shopping mall in Oregon or a temple in Wisconsin or a movie theatre in Aurora or a street corner in Chicago," he said, referring to other US shootings this year.

"We`re going to have to come together and take meaningful action to prevent more tragedies like this, regardless of the politics," he added.