Rome, January 5 - A visibly emotional President Barack Obama, at one point wiping tears from his cheek, unveiled his plan Tuesday to tighten control and enforcement of firearms in the U.S., using his presidential powers in the absence of legal changes he implored Congress to pass, the Associated Press reported. Obama accused the gun lobby of taking Congress hostage, but said "they cannot hold America hostage." He insisted it was possible to uphold the Second Amendment while doing something to tackle the frequency of mass shootings in the U.S. that he said had become "the new normal." "This is not a plot to take away everybody's guns," Obama said in a ceremony in the East Room. "You pass a background check, you purchase a firearm. The problem is some gun sellers have been operating under a different set of rules." Obama wiped tears away as he recalled the 20 first-graders killed in 2012 at Sandy Hook Elementary School. He paid tribute to the parents, some of whom gathered for the ceremony, who he said had never imagined their child's life would be cut short by a bullet. "Every time I think about those kids, it gets me mad," Obama said.