The attendance of the Newtown families comes as lawmakers continue to push for measures to reduce gun violence.
In the aftermath of the December shooting massacre at Sandy Hook Elementary School, President Obama urged Congress to enact a number of new measures, including universal background checks on gun purchases and bans on the sale of assault weapons and high-capacity magazines. The massacre resulted in 28 dead, including 20 children, and renewed debate over the nation's gun laws.
The Senate is expected to vote on a gun bill which includes provisions expanding background checks and enacting tougher penalties on gun traffickers. But Senate Majority Leader Harry Reid (D-Nev.) excluded many more controversial provisions backed by the White House, claiming they could drag down the entire gun bill. Reid has said he would allow votes on banning assault weapons and high-capacity clips as amendments.
Last week, Obama made an emotional plea at a White House, where he was joined by mothers of victims to gun violence, including some from Newtown.
"Shame on us if we've forgotten," said Obama of the tragedy, urging lawmakers to pass meaningful gun control.
Recently, Vice President Biden, who headed the White House task force on gun violence, has been calling his former colleagues to rally support for new gun measures. Biden recently also sat down privately with Republican senators John McCain (Ariz.), Lindsey Graham (S.C.), and Johnny Isakson (Ga.), to discuss gun control.