New York City Mayor Michael Bloomberg, the country's most prominent voice on gun control until President Obama took strong action on the issue this week, continued beating the drum for his priorities at a conference of the country’s mayors Friday afternoon.

Universal background checks for prospective gun buyers, he said, should be the “law of the land,” adding that "we've got to do something about this."

The politically independent mayor -- who has studiously resisted being aligned with either party, though only Democrats seem at all interested in what the policies he is urging -- told the U.S. Conference of Mayors that “background checks for all gun sales will dramatically reduce the illegal traffic that leads to murder."

"It will dramatically reduce domestic violence. It will dramatically reduce suicides. It’s a law that works, and we’ve got to tell our members of Congress that it is time to make it the law of the land," he said.

Bloomberg's vehemence on universal background checks echoed remarks made earlier Friday by summit panelist Attorney General Eric Holder, who called on Congress to “move swiftly” to pass legislation requiring such checks.

Bloomberg  has stepped up his involvement in the national gun-control debate in recent years, spending $10 million through his super PAC during the 2012 election cycle to try to defeat candidates of either party who favor lax gun restrictions.

This week, he was somewhat eclipsed on the issue by Obama, who at a White House news conference on Wednesday rolled out a package of executive actions on gun reform in response to last month’s Newtown, Conn., elementary school shooting.

On Friday, the Big Apple's mayor praised the move by Obama and Vice President Biden, who he said “did step up” on fighting gun violence and included in their  agenda “virtually every one of the major elements” sought by Mayors Against Illegal Guns, the 800-member advocacy group spearheaded by Bloomberg.

“I give them both a lot of credit for listening to the voices of everyday Americans and putting public safety ahead of special interests. The public in this country has changed their views,” Bloomberg said, citing as an example Joe Scarborough, the MSNBC host and former Republican congressman who recently shifted course and argued in favor of stricter gun laws.

Apart from universal background checks, Bloomberg also voiced support for other parts of the Obama administration’s plan and sharply criticized the country’s current enforcement of laws governing gun purchases.

“Criminals and the mentally ill are prohibited, as you know, by federal law from owning guns, but as you know, the enforcement of that law is a tragic joke,” he said. “And all of us have to deal with the results of that. Criminals can buy guns as easily as logging onto the Internet or just by stopping by a gun show, and there’s no background check.”

Bloomberg argued, as he did during a CNN interview Thursday night, that while stricter gun regulations won’t prevent every tragedy, that shouldn’t be a reason for federal lawmakers to avoid taking any action on the issue. And he called on mayors to take an active role in pressing Capitol Hill to approve tighter gun laws, since “Congress is more removed from this issue than mayors are.”

He quipped that Martin Luther King Day, which the country will celebrate, along with Obama's second inauguration, on Monday, is the closest thing that America has to a national day of remembrance for victims of gun violence. And he disputed the argument by gun-control opponents that the Obama administration is seeking to tamp down on Second Amendment rights.

“Keeping guns away from criminals and other dangerous people has nothing to do with the Second Amendment,” Bloomberg said. “And it’s not something that we can do very effectively at the local level. This is not a constitutional question, but it is a political courage issue and it is an issue for Washington. We can’t do it alone.”

If lawmakers don’t exhibit that “political courage,” he warned, then “we will stand up for whoever runs against them.”