The House Appropriations Committee sent a letter to Attorney General Loretta Lynch on Monday to remind the Obama administration that any gun-related executive action should not interfere with financial resources already allocated by Congress.
"I want to express the committee's expectation that the Department of Justice will allocate its resources to the enforcement of existing federal law," wrote Republican Rep. John Culberson, chairman of the House Commerce, Justice, Science and Related Agencies subcommittee.
The GOP-led committee also warned Lynch that any attempt by the Obama administration to implement "unlawful limitations on the unambiguous Second Amendment rights of Americans" would not be funded.
The administration is preparing its fiscal 2016 spending plan and 2017 president's budget request.
The White House is expected to disclose some of the gun-control plan Monday night. President Obama is scheduled to announce the full executive actions Tuesday morning.