His speech also comes as Obama and some lawmakers focus on passing gun control measures. Polls show more people are warming up to the possibility.

Last week, Obama proposed background checks on all gun sales, and bans on military style assault weapons and high-capacity magazines.

With relatives of some of the 20 children killed in the Connecticut rampage looking on, Obama also signed 23 executive actions -- which don't require congressional approval -- to strengthen existing gun laws. They also take related steps on mental health and school safety.

In his speech Tuesday, LaPierre set his sights on Obama's proposal to expand background checks to anyone buying a gun whether at a store or in a private sale at an auction or convention.

"There are only two reasons for that federal list of gun owners --- to tax them or take them," he told the cheering crowd.

The tit-for-tat continues a running battle between the president and the powerful gun lobby.

Last week, the NRA released an advertisement that called the president an "elitist hypocrite," and asked why he opposes the idea of placing armed guards in every school -- a proposal pushed by the NRA -- despite the fact that his own children attend a school with similar security.

The ad was only slated to air on the Sportsman Channel, but has gained strong media attention, both on the airwaves and online. It has also garnered criticism.

Republican Gov. Chris Christie of New Jersey criticized it for making a reference to the president's children in a political attack commercial.

Speaking at a news conference last week, the outspoken governor decried the move as "reprehensible" and argued that the group lost some credibility by making the ad.