President Barack Obama proposed a new assault weapons ban and mandatory background checks for all gun buyers on Wednesday as he tried to channel national outrage over the massacre at the Newtown, Conn., elementary school into the biggest U.S. gun-control push in decades, according to Reuters.

Rolling out a wide-ranging plan for executive and legislative action to curb gun violence, Obama presented his agenda at a White House event in front of an audience that included relatives of some of the 20 first-graders who were killed along with six adults in the December 14 massacre at Sandy Hook Elementary School.

The proposals stem from a month-long review led by Vice President Joe Biden, who – on orders from Obama – met with advocates on both sides, including representatives from the weapons and entertainment industries, Reuters reports.

The plan calls on Congress to renew a prohibition on assault weapons sales that expired in 2004, a requirement for criminal background checks on all gun purchases – including at gun shows – and a new federal gun trafficking law, which has been long sought by big-city mayors to keep out-of-state guns off of their streets, the article says.

President Obama also announced 23 steps he intends to take immediately without congressional approval. These include improvements in the existing system for background checks, lifting the ban on federal research into gun violence, putting more counselors and “resource officers” in schools, and providing better access to mental health services, Reuters reports.

However, the proposed assault weapons ban is the most politically contentious component in Obama’s plan. In his speech at the event, Obama “acknowledged the political challenges but made clear that he is prepared to take on the National Rifle Association, despite its widespread support among Republicans and significant backing among Democrats,” the article says.