"This is an essential first step toward ensuring we reduce the number of mass shootings in America, keep guns out of the hands of criminals, and save lives", Masto, one of the bill co-sponsors said.
Under current US laws, unlicensed or private gun sellers may transfer firearms without background checks. Research on the subject suggests that nearly 25 percent of all gun transfers in the United States happen without a background check.
READ MORE: US Gun Rights Watchdog Might Sue Over Decision to Ban Bump Stocks
The current proposal would expand federal background checks to all firearm transfers, excluding transfers between law enforcement officers, temporary loans, inheritance or gifts to immediate family members, according to the bill.
The issue of gun violence in US schools has become an increasing concern in the country following several mass shootings, including one last February at the Stoneman Douglas school in Florida, where a former student killed 17 people.