HACKENSACK -- Former congresswoman Gabby Giffords took the stage alongside Democratic candidate for New Jersey governor Phil Murphy on Thursday evening to call for tightening the state's already strict gun laws.

"I've seen great courage when my life was on the line," said Giffords, who has advocated for gun control since her own near-fatal shooting in 2011, during a Murphy campaign stop at the Logan Family Life Center.

"Now is the time to come together and be responsible."

Murphy, who is running against Republican nominee Kim Guadagno, has called for greater restrictions on access to firearms by those considered a danger to themselves or others, and for expanding smart gun technology, among other measures.

The former U.S. ambassador to Germany appeared alongside Giffords and her husband, astronaut and New Jersey native Mark Kelly, to push for tighter restrictions and better cooperation with neighboring states to prevent the flow of illegal guns into New Jersey.

The Garden State already has among the toughest gun laws in the country, and gun rights advocates here have long complained about onerous wait periods and delays in the permitting process for handguns.

Efforts by Democrats in the Legislature to further tighten restrictions in the aftermath of several mass shootings have been thwarted by Gov. Chris Christie.

Murphy said there was a "black and white choice" between himself and Guadagno, a Republican former county sheriff who has received an "A" rating from the National Rifle Association.

"The only 'F' I'll ever be proud of in my life is the 'F' from the NRA," Murphy told the crowd, referring to the failing grade the gun rights group gave him.

Guadagno, Christie's lieutenant governor, has said she supports enforcing the state's existing gun laws and would consider strengthening background checks and penalties for gun crimes.

Kelly, who was born in West Orange and has appeared alongside his wife to push for new gun laws in Trenton in recent years, said it had "been quite a challenge" getting support for additional measures from Guadagno and Christie.

"We can't get sensible laws passed here in New Jersey because of the person who occupies the governor's office," Kelly said. "We're going to change that."

S.P. Sullivan may be reached at ssullivan@njadvancemedia.com. Follow him on Twitter. Find NJ.com on Facebook.