Six hundred American mayors initiated a bipartisan ad campaign Tuesday, urging Congress to fill glaring gaps in U.S. gun laws, according to a press release posted on PR Newswire. The ad draws attention to an al-Qaida propaganda video released June 3, which encourages terrorists to capitalize on weak U.S. gun restrictions.

"America is absolutely awash with easily obtainable firearms," stated American-born terrorist Adam Gadahn, a.k.a. Azzam al-Amriki, encouraging "lone wolf" terrorists to inflict "major damage" on "the enemies of Islam."

"You can go down to a gun show at the local convention center and come away with a fully automatic assault rifle without a background check and, most likely without having to show an identification card. So what are you waiting for?"

While the public cannot legally purchase fully automatic weapons, the terrorist video points out pronounced weaknesses in firearms regulation. Private dealers—who account for roughly 40 percent of U.S. gun sales, according to the press release—do not conduct background checks, and sell in places ranging from gun shows to the Internet.

The al-Qaida video also identifies a second major security gap in U.S. national security: federal authorities have not passed legislation preventing terror suspects, including those on government watch lists, from purchasing guns and explosives.

This loophole pertains to any and all weapons readily available to the public, such as semi-automatic assault weapons and other "military-style weaponry."

The mayors who launched the ad campaign, titled "What Are You Waiting For," emphasize the importance and widespread support for fixing this security gap. "Criminals already know how to take advantage of gaps in our gun laws, and now Al Qaeda knows, too," said New York City Mayor Michael R. Bloomberg. "Americans, including NRA members, overwhelmingly support stronger laws to keep guns away from terrorists and other dangerous people."

Pending legislation, such as the Fix Gun Checks Act (S.436/H.R.1781) and the Denying Firearms and Explosives to Dangerous Terrorists Act (S.34/H.R.1506), aims to close the private-sale loophole and grant the Attorney General discretion to block firearm sales to terror suspects.

Gun owners and private citizens alike support these initiatives with a January 2011 poll finding 86 percent of Americans and 81 percent of gun-owning Americans supporting universal background checks and 88 percent of both groups supporting the banning of sales to individuals on terror watch lists.