WASHINGTON — Maine Sen. Angus King is co-sponsoring a bill to require that the White House obtain an independent analysis before using drones or other lethal force to kill U.S. citizens suspected of working overseas with terrorists.

King and Sen. Marco Rubio, R-Fla., released their bill on the same day that President Obama is expected to address drone strikes and other counter-terrorism issues in a speech at the National Defense University.

The King-Rubio legislation would require that the director of national intelligence create an independent “red team” that analyzes the data purporting to support a “targeted strike” against U.S.. citizens and report back to intelligence agencies within 15 days. The bill would also require that the agencies notify congressional intelligence agencies about the individual and the “red team” analysis.

King, an independent who caucuses with the Democrats, has raised concerns about the lack of oversight of targeted killings of American citizens working with overseas terrorist organizations.

“Our nation is facing serious threats to our security – and it is vital that our government have the tools and the authority to prevent terrorists from killing Americans,” King said in a statement. “I also firmly believe that the executive branch being the prosecutor, the judge, the jury, and the executioner is very contrary to the traditions and laws upon which this nation was founded.”

On Wednesday, the Obama administration disclosed to members of Congress that they have killed four U.S. citizens through targeted killings. At least three of the individuals were killed by drone strikes by the CIA.

This story will be updated.