With a major oil company fearful of the security situation in Yemen, the U.S. State Department said it's confident the government in Sanaa will stay in place.

The Yemeni government is facing dueling threats from the northern Houthi rebel movement and southern separatist groups that at times have been associated with al-Qaida.

U.S. State Department spokeswoman Jen Psaki told reporters during her regular press briefing she was concerned especially by Houthi rebel action, adding they were inconsistent with existing national partnership agreements.

Longtime Yemeni President Ali Abdullah Saleh stepped down in the aftermath of the Arab democratic revolts known as the Arab Spring. Psaki said Wednesday she was confident the government of President Abd Rabbuh Mansur Hadi, which replaced Saleh's, would stay in place amid the latest pressure.

Her confidence came the same day that Norwegian energy company DNO International declared force majeure in Yemen, meaning it was freed from contractual obligations because of circumstances beyond its control.

"Production in the republic of Yemen remains stable at over 7,000 barrels per day across the operated and non-operated blocks, notwithstanding the current security and political environment," the company said. "However, DNO is not yet able to resume drilling activities or the development of previous discoveries [because of insecurity]."