Mitt Romney will address the National Rifle Association, or NRA, on Friday along with candidate Newt Gingrich.
The NRA's annual meeting is taking place in St. Louis.
Romney advisers told CNN that his speech on Friday marks the launch of the general election campaign against President Barack Obama. Romney's NRA speech is said to be the first in a series that will take place over coming months, but his advisers have not announced any dates and topics.
Gun laws are now at the forefront following the shooting death of unarmed Florida teenager Trayvon Martin. Martin's killing has caused much debate about the Stand Your Ground laws in Florida and other states, which grant legal protections to people who use lethal force against a home.
Former Pennsylvania Sen. Rick Santorum will also share the stage. He dropped out of the running last Tuesday.