NRA executive vice president Wayne LaPierre has told a news conference that "now is the time to speak about protecting American children.
Speaking for the first time since the Sandy Hook school shootings, he told reporters federal gun prosecutions have decreased and the media promotes violence through video games, adding that the media also demonises lawful gun owners.
More top news
The Islamic centre where the Manchester suicide bomber is thought to have prayed says the attack "has no place in Islam or any religion".
German chancellor Angela Merkel and Indian prime minister Narendra Modi among those to praise "great spirit" of Manchester people.
The bomber's identity has been confirmed by Greater Manchester Police.