President Barack Obama on Tuesday unveiled new measures that would govern gun sales and safety in the United States, actions he said are geared toward reducing gun violence by preventing the weapons from ending up in the hands of people who may use them nefariously.

Speaking in a televised address from the East Room of the White House, Obama listed mass shootings while detailing an executive order he said were designed to close loopholes in existing laws and make it tougher for people to obtain the weapons used in the deadly rampages.

The new measures would enhance the vetting process, requiring anyone who is “in the business of selling firearms” to obtain a selling license and conduct background checks. That’s not always the case under the current system, which has more lenient rules for gun-show and online sales.

“We know that we can’t stop every act of violence,” Obama conceded. “But what if we tried to stop even one?”

Opponents and gun rights activists immediately spoke out against Obama’s order, saying the president’s actions can not usurp American’s constitutional right to bear arms. House Speaker Paul Ryan (R-Wisconsin) issued a statement in which he said the president’s “words and actions amount to a form of intimidation that undermines liberty,” and said there was “no doubt” that someone would challenge the directive, which doesn’t need Congressional approval, in court.

In his address, Obama said the order was not an infringement of the Second Amendment and noted Americans were guaranteed additional rights and freedoms that gun violence was hampering, noting guns contribute to the deaths of 30,000 Americans every year. The president expressed a need to balance those other freedoms and rights with the right to bear arms.

He specifically mentioned the rights to life, liberty and the pursuit of happiness.

“Those rights were stripped from college kids in Blacksburg and Santa Barbara and from high schoolers at Columbine and from first-graders in Newtown,” Obama said, referencing campus shootings at Virginia Tech, UC Santa Barbara, Columbine High School and Sandy Hook Elementary School. “And from every family who never imagined that their loved one would be taken from our lives by a bullet from a gun. Every time I think about those kids, it gets me mad.”

Obama also referenced mass shootings at a military facility in Fort Hood, Texas, a church in Charleston, South Carolina, the Washington Navy Yard, a holiday party in San Bernardino, California, and a movie theater in Aurora, Colorado, on a list that included “too many” instances of gun violence. The president said it was time “not to debate the last shooting, but do something to try to prevent the next one.”

Several Democrats lauded the president’s efforts. They include former Arizona Congresswoman Gabrielle Giffords, who was injured during a mass shooting in Tuscon five years ago this week. She attended the address and tweeted Obama’s “responsible actions … will save lives.”

However, the National Rifle Association issued a statement saying that none of Obama’s proposals would have stopped any of the “horrific events he mentioned” during his speech.

“Once again, President Obama has chosen to engage in political rhetoric, instead of offering meaningful solutions to our nation’s pressing problems,” Chris W. Cox, the executive director of the association’s Institute for Legislative Action, said in a statement. “Today’s event also represents an ongoing attempt to distract attention away from his lack of a coherent strategy to keep the American people safe from terrorist attack. The American people do not need more emotional, condescending lectures that are completely devoid of facts.”

The main point of Obama’s executive order is undoubtedly reforming background checks.

Those checks have already prevented 2 million guns from being sold to people who cannot legally purchase them, the White House said in a news release, and the executive order aims to bolster the strength and overall efficiency of the system. The FBI is planning to hire 230 additional employees to process the 63,000 background check requests it receives every day, and the Bureau of Alcohol, Tobacco & Firearms is working to finalize rules that would prevent people from circumventing the background check requirements for particularly dangerous guns.

The order also calls for better enforcement of existing gun laws, and Obama’s budget for fiscal year 2017 includes funding that would allow the Bureau of Alcohol, Tobacco & Firearms to hire 200 additional agents and investigators. The president is also pushing for better gun safety technology, directing officials with the Homeland Security, Justice and Defense departments to help study how to prevent guns from firing accidentally, and proposing $500 million for nationwide improvements to mental health treatment.