NRA Chief Executive Wayne LaPierre has told a news conference that lives could have been saved at Sandy Hook Elementary School if security at the school had been armed.
He also told reporters: "The only thing that can stop a bad guy with a gun, is a good guy with a gun."
More top news
After the heatwave come the storms, with lightning flashes illuminating the night sky across much of the country last night.
An Independence Day event at a UK base has been cancelled by the US Air Force over security fears.
British firms predict the economy should sustain a "solid" pace of growth for the rest of the year thanks to lower oil prices and inflation.