US President Barack Obama has said action must be taken for new gun safety laws in the wake of the Newtown massacre, saying "shame on us if we've forgotten" the pledge made for the school victims.
"We need everybody to remember what we felt less than 100 days ago and make sure what we said wasn't just a bunch of platitudes," Mr Obama said at the White House.
"The entire country was shocked and pledged we'd do something about it and this time it'd be different," he said.
The president said the gun lobby contains "powerful voices" whose "assumption is that people will just forget about" the demand for tighter laws made after the December killings.
But Mr Obama said: "Nothing is more powerful than millions of people calling for change."
More top news
MPs say there must be no way back for the former London mayor as he hints he could seek to rejoin the party.
President Donald Trump has requested that the Justice Department investigates whether the FBI infiltrated his campaign.
High pressure will help keep conditions relatively quiet through the course of this week.