WASHINGTON – One day after President Obama unveiled his far-reaching proposal for gun-policy reform at an emotional White House news conference, Vice President Biden renewed the administration’s call for action, telling a summit of the nation’s mayors that the issue is “more urgent and immediate” than any other facing the country.

Speaking Thursday at the winter meeting of the U.S. Conference of Mayors, Biden delivered a point-by-point defense of the White House gun agenda that he helped to spearhead, using stark, often personal language.

“I know we don’t have absolute unanimity in this ballroom — nor do we in any ballroom — but we all know, everyone acknowledges we have to do something,” Biden told the crowd of mayors. “We have to act. And I hope we all agree that there’s a need to respond to the carnage on our streets and in our schools.

“I hope we all agree that mass shootings like the ones that we witnessed in Newtown 34 days ago cannot continue to be tolerated,” he said, calling the tragedy one that “in all my years in public life, I think, has affected the public psyche in a way that I’ve never seen before.”

Since being tapped last month to serve as the Obama administration’s point man on gun policy reform in the wake of the Newtown, Conn., elementary school shooting, Biden has met with more than 200 groups representing a range of stakeholders on the issue.