WASHINGTON, Oct. 25  Secretary of State Condoleezza Rice conceded on Thursday that there was a “hole” in United States law that had allowed Blackwater USA employees and other armed contractors in Iraq to escape legal jeopardy for crimes possibly committed there.

In an appearance before the House Oversight and Government Reform Committee, Ms. Rice said the administration would support new laws that would apply to contractors but expressed reservations about proposals to bring contractors under the military justice system.

She deferred a number of other questions about problems with the supervision of the thousands of private security guards in Iraq, saying she planned to meet with Robert M. Gates, the secretary of defense, to try to come up with new rules to avoid episodes like the shooting by Blackwater gunmen on Sept. 16 that Iraqi investigators have said left 17 Iraqis dead. “Obviously we need a better coordinated policy for all of them,” she said.

Blackwater, meanwhile, under continuing siege in the courts, the news media and Congress, stepped up its public relations efforts this week with a mass e-mail message to its employees, suppliers, fellow security contractors and political allies, asking them to flood Congress with messages of support.