Newly appointed U.S. Defense Secretary Leon Panetta is concerned over Iranian weapons provided to Iraqi insurgent groups.

“There is concern with security there and what is being done to stop the Iranian weapons from coming into Iraq,” he said ahead of his meetings with senior Iraqi officials, defense department’s official website reported. He added U.S. lost 15 troops in June 2011.

The official stressed that U.S. will withdraw forces from Iraq by the end of this year.

“The drawdown is based on an agreement and presidential guidance, but the insurgents and Iranian groups are trying to create the impression that we are being driven out,” Panetta said.