US Vice-President Joe Biden (L) makes remarks next to Philadelphia Mayor Michael Nutter at the conclusion of a roundtable discussion on gun control at Girard College in Philadelphia, Pennsylvania, Feb 11, 2013. Biden was joined by members of law enforcement and politicians to discuss gun law reforms.[Photo/Agencies]

PHILADELPHIA - US Vice-President Joe Biden, speaking hours after a fatal shooting at a courthouse in his home state of Delaware, said on Monday there was an unprecedented sense of urgency among police and officials to enact gun control laws.

"The one thing that came across to me in talking with the mayors and law enforcement officers that are here is a real sense of urgency," Biden said after meeting Philadelphia Mayor Michael Nutter, police chiefs, three US representatives and a US senator.

He cited the shooting in Wilmington, Delaware, in which three people died and two were wounded in the New Castle County Courthouse.

He also referred to the Dec 14 mass shooting at an elementary school in Newtown, Connecticut, in which 20 children and six adults died.

"We can't wait, we cannot wait, the images of those innocent little children being riddled with bullet holes has gripped the conscience of the nation, and the nation is demanding that we act responsibly," he said.

Gun control is likely to be a main topic of President Barack Obama's State of the Union speech on Tuesday night.

Last month Obama launched the biggest US gun-control push in generations, urging Congress to approve an assault weapons ban and background checks for all gun buyers to prevent mass shootings like the one in Newtown.

Many of the president's proposals face tough opposition from gun enthusiasts led by the powerful National Rifle Association.

Bringing back the military-style assault weapons ban that lapsed in 2004 would be particularly difficult because of resistance from Republicans and some Democrats in Congress.