Congress is moving to put under military control all armed contractors operating in combat zones, a Pentagon recommendation that could run into resistance at the State Department.

The Senate this month included such a requirement in its 2008 defense spending bill. Democratic Sen. Carl Levin, chairman of the Senate Armed Services Committee, told reporters Wednesday he is confident the House will go along with the idea and include it in a final bill sent to President George W. Bush.

Secretary of State Condoleezza Rice was to testify about the subject Thursday before the House Oversight and Government Reform Committee.

She has ordered new rules for the private guards who are hired to protect U.S. diplomats. They include increased monitoring and explicit rules on when and how they can use deadly force. The steps were recommended by a review panel that Rice created after a deadly Sept. 16 shooting involving Blackwater USA guards.

Rice also urged better coordination with the military, but did not explicitly act on a suggestion by Defense Secretary Robert Gates that combatant commanders have control over the contractors.

Levin said he was not sure if Rice expressly opposed the idea. "Whether she likes it or not, we expect to get this language" to emerge in the compromise with the House.

"It's not slapdash" and "is something we've been working on a long time," Levin said.

The Blackwater shooting provoked an outcry from the Democratic-led Congress and the Iraqi government, which is demanding that it have the right to prosecute the contractors.

In more fallout, the State Department's security chief resigned Wednesday.

Richard Griffin, the assistant secretary of state for the Bureau of Diplomatic Security, made no mention of the furor in his resignation letter to Bush and Rice. But it came just one day after a study commissioned by Rice found serious lapses in the department's oversight of private guards, who are employed by Griffin's bureau and report to it.

Rice accepted the resignation, which is effective Nov. 1, State Department spokesman Sean McCormack said. Griffin will be replaced on an acting basis by one of his deputies, Gregory Starr.

Griffin, who previously was deputy director of the U.S. Secret Service and inspector general for the Veterans Affairs Department, had been in his current job since June 2005.