US Vice President Joe Biden convened the first meeting of the White House's gun-control working group on Thursday, bringing together law enforcement officials and Cabinet secretaries.

Biden said the group would work to find "a comprehensive way in which to respond to the mass murder of our children that we saw in Connecticut."

The vice president said there was "no reason" why an updated assault weapons ban could not pass Congress. He said he would call on the law enforcement officials to help in a legislative push against "everything from cop-killer bullets to type of weapons that should be off the street."

Attorney General Eric Holder, Secretary of Education Arne Duncan, Homeland Security Secretary Janet Napolitano, Secretary of Health and Human Services Kathleen Sebelius, and top White House aides attended the meeting.

US President Barack Obama on Wednesday announced the gun- control task force led by Biden to be charged with guiding the administration's continuing response to calls of gun control after the Connecticut elementary school massacre.

Obama promised the taskforce would make proposals for new laws and actions in January, and he would push the new gun control proposals in Congress.

Biden will work with cabinet members and outside groups to formulate the recommendations, as the president called on Congress to reinstate an assault weapons ban that expired in 2004 and to pass legislation that would close the gun show loophole, which allows people to purchase firearms without a background check.

In addition to bans on the sale of assault weapons and high- capacity ammunition clips, the White House would push a law that requires background checks on all gun purchases to prevent legal loopholes, said the White House spokesman Jay Carney during a daily briefing on Thursday.

Carney added that the president would also call on Congress to "take action to improve coordination between the federal government and state and local law enforcement to keep illegal guns out of the hands of criminals."

A gunman on last Friday opened fire in Sandy Hook Elementary School in Newtown, killing 20 kids and 6 adults, before committing suicide. The same shooter killed his mother earlier in the day at her home near the school.