Washington, January 16 (RHC)-- U.S. lawmakers are seeking to block President Barack Obama’s plan to shift control of the country’s drone campaign from the CIA to the Pentagon. Congress has moved to insert a secret provision in the $1.1 trillion government spending bill introduced this week that would preserve the spy agency’s role in lethal operations overseas.

U.S. drone strikes in Afghanistan, Pakistan, Yemen and several other countries have left thousands of civilians dead since 2004, when the controversial campaign began to apparently target “suspected militants” in foreign nations. The U.S. congressional measure “would restrict the use of any funding to transfer unmanned aircraft to the authority to carry out drone strikes from the CIA to the Pentagon,” The New Times reports, citing American officials. Critics say the provision is a direct intervention by lawmakers into the way covert operations are run.

Last month, a U.S. drone strike in Yemen killed six civilians. U.S. officials said the attack was aimed at a senior al-Qaeda operative. On Wednesday, another strike killed a farmer in the country.

The collateral damage that has accompanied drone strikes has generated growing opposition in the U.S. to removing the CIA from such operations anytime soon.