Vice President Joe Biden took his gun control show into the heart of Virginia gun country Friday, defending and seeking support for a White House plan on reducing firearm violence.

Biden led a two-hour roundtable meeting with US lawmakers, administration officials and local leaders in the capital Richmond -- once a city with one of America's highest crime rates.

Taking part in the talks were psychiatrists and other experts who have studied the kinds of behavior that led to shootings such as the one last month in Newtown, Connecticut that left 20 schoolchildren and six adults dead, and the 2007 slaughter at Virginia Tech University that claimed 33 lives.

"We can not remain silent as a country" after the Newtown massacre, Biden said after the meeting, adding that he had met with parents of many of the slain children when President Barack Obama tasked him with drawing up recommendations for how to reduce gun-related deaths.

"It is a national tragedy, and a window into the vulnerability people feel about their safety and the safety of their children," Biden said.

"We have an obligation to act, not wait."

Biden mentioned several pathways being explored, including adding more officers to police forces, training more experts in analyzing and detecting dangerous behavior, making criminal background checks universal for all gun purchases, and ensuring that those ruled to have mental problems be listed in a national database.

"Tens of thousands of those adjudications... have not been transferred to the National Instant Criminal Background Check System, Biden said.

Virginia, south of Washington, illustrates several difficulties in the fight against gun violence and proliferation. The driving force in the gun lobby, the National Rifle Association, is headquartered in the state, and firearms can legally be carried openly.

In 2012 under Republican governor Bob McDonnell, the state repealed a law that prohibited buying more than one gun per month.

Biden's visit came as Democrats in Congress launched a campaign to toughen gun laws, including introduction of a beefed up version of an assault weapons ban that was allowed to lapse in 2004 after 10 years on the books.

"With the help of our colleagues in the House and Senate we're going to get something done that is going to improve the prospects of reducing gun violence in the United States," the vice president said.

Securing congressional action will be tricky, with several Republicans going on record saying they opposed the White House's gun control plans because they believe the measures would infringe on Americans' constitutionally enshrined right to bear arms.

And opposition is not purely along party lines; with some Democrats from states where hunting and sport shooting are popular supportive of gun rights.

An ABC News poll this week found 53 percent of Americans support Obama's gun control plan, while 41 percent view it unfavorably.

Next week a US Senate committee will hold a hearing on gun violence, with NRA executive Vice President Wayne LaPierre among those scheduled to testify.