Obama to unveil gun violence measures Wednesday WASHINGTON (Reuters) - President Barack Obama will unveil on Wednesday a series of "concrete proposals" to counter gun violence that will include a push for an assault weapons ban and measures to strengthen background checks for gun buyers. White House spokesman Jay Carney said Obama and Vice President Joe Biden, who led a task force that developed recommendations on the issue, would present the package of legislative and executive measures at a White House event at 11:45 a.m. Children from around the country who wrote letters to the president expressing concern about gun violence and school safety were to attend the event with their parents. "The president has made clear that he intends to take a comprehensive approach," Carney told reporters. "There are specific legislative actions that he will continue to call on Congress to take, including the assault weapons ban, including a measure to ban high-capacity magazine clips, including an effort to close the very big loopholes in the background check system in our country," he said. Biden delivered his recommendations to Obama after a series of meetings with representatives from the weapons and entertainment industries requested by the president after the December 14 school shooting in Newtown, Connecticut, in which 20 children and six adults were killed. Obama, who has said the day of the shooting was the worst of his presidency, said on Monday he would study the panel's ideas and then move forward "vigorously" on those that he endorsed, including some actions he could take without congressional approval. Reporting by Jeff Mason; Editing by Cynthia Osterman