US President Barack Obama has called for tougher background checks on Americans trying to buy a gun as he and Republican challenger Mitt Romney engaged in their most extensive discussions on the gun control issue since last week's massacre in a Colorado theater.
Their pointed comments revived a debate - if briefly - that has faded to the background in national politics and been virtually non-existent in this year's close presidential race.
Mr Romney said in a television interview that changing the nation's laws would not prevent gun-related tragedies. He mistakenly said many weapons used by the shooting suspect were obtained illegally. Authorities say the firearms used to kill 12 people and injure dozens were purchased legally.
In his speech to the National Urban League civil rights group, Mr Obama said he wanted a national consensus in the effort to stem gun violence.
Despite the Second Amendment's protection of gun rights, Mr Obama said, "I also believe that a lot of gun owners would agree that an AK-47 belongs in the hands of soldiers, not in the hands of criminals - that they belong on the battlefield of war, not on the streets of our cities."
Gun control is a hotly partisan issue in the US. The powerful National Rifle Association, which fights gun control and has huge sway in Congress, has successfully made the issue nearly off limits among most legislators who fear the group's opposition at re-election time.
The Brady Campaign to Prevent Gun Violence challenged both Mr Obama and Mr Romney today to lead a search for solutions to gun violence.
The group's president, Dan Gross, said it's shameful for leaders to play politics with the issue when lives could be saved.
The White House has faced fresh questions since the shootings about whether Obama, a strong supporter of gun control while a senator from Illinois, would make an election-year push for stricter measures.
Mr Obama acknowledged a national pattern of failing to follow through on calls for tougher gun restrictions after violent crimes.