WASHINGTON (AP) - Gun control legislation that the US Senate will debate next month will include an expansion of federal background checks for firearms buyers, Majority Leader Harry Reid said, indicating that lawmakers' most effective possible response to the December school massacre will move forward.
The shooting that left 20 young children dead brought gun safety back as a top national issue, and President Barack Obama's administration moved quickly to win lawmakers support for several gun safety proposals before the high emotions faded.
But this week, Mr Reid said the most controversial proposal, an assault weapons ban, had been dropped to make the remaining legislation to win approval in the Senate, which is controlled by Democrats but has plenty of gun rights supporters - or lawmakers supported by gun-rights groups.
Many gun supporters argue that gun restrictions run counter to the constitutional right to bear firearms.
Democrats intend to take an aggressive approach in the effort to broaden the background checks, which currently required for transactions involving federally licenced firearms dealers but not private sales at gun shows or online.
The background check system is designed to keep guns from criminals, people with serious mental problems and others considered potentially dangerous.
The overall gun measure will also include legislation boosting penalties for illegal gun trafficking and modestly expanding a grant programme for school security, said Mr Reid.
The measure's fate remains uncertain, and it will all but certainly need Republican support to survive.
Mr Reid said that during Congress' upcoming two-week break, he hopes senators will strike a bipartisan compromise on broadening background checks. Without a deal, he indicated the bill would include a stricter version approved this month by the Senate Judiciary Committee that would the system to virtually all private gun transactions with few exceptions.
"I want to be clear: In order to be effective, any bill that passes the Senate must include background checks," Mr Reid said in a written statement.
Opponents, including the National Rifle Association (NRA), say background checks are easily sidestepped by criminals and threaten creation of a government file on gun owners - which is illegal under federal law.
"We remain as committed as we have been to opposing gun bans. History shows us that gun bans don't work to reduce crimes," said Andrew Arulanandam, an NRA spokesman.
The NRA wants Congress to fund more armed guards at schools, step up prosecutions of people who file false gun applications and increase the background check system's access to state records of people with serious mental illness and other problems.
"Senator Reid's announcement is a tremendous step and we recognize there is still a tough road ahead," said Mr Dan Gross, president of the Brady Campaign to Prevent Gun Violence.
Mr Reid said he will allow votes on amendments including an assault weapons ban, curbs on high-capacity ammunition magazines and mental health. There is wide-ranging agreement that many states poorly report mental health records to the federal background check system.
The assault weapons ban's sponsor, Senater Dianne Feinstein, plans to offer the provision as an amendment that seems certain to lose.