U.S. Defense Secretary Leon Panetta says the U.S. is concerned about a new long-range rocket and mobile launch pad that North Korea displayed during a recent military parade.

Panetta said during a House Armed Services Committee hearing on Thursday that the Pentagon is trying to figure out whether the new missile spotted at the parade is an intercontinental ballistic missile.

In an interview with CNN, Panetta said that the threat posed by North Korea is keeping him awake at night, adding that the U.S. is prepared for "any contingency" when it comes to dealing with the communist state.

Meanwhile, State Department Spokesman Mark Toner said “China has provided repeated assurances that it is complying fully with both Resolution 1718 as well as 1874,” which ban the provision of weapons materials.

He made the remark after being asked to comment on reports that U.S. Congressman Mike Turner sent a letter to U.S. Secretary of State Hillary Clinton about the new mobile missile shown at a recent military parade in Pyongyang.

In the letter, Turner said the photos of the new missile suggest cooperation and support from China and asked if such cooperation would be in violation of the UN Security Council resolutions.