America’s defense chief reiterated the Obama administration’s firm opposition to containing a nuclear Iran, saying U.S. policy must focus on preventing Tehran from acquiring a nuclear weapon.

“This is not about containment,” Defense Secretary Leon Panetta said on Thursday, May 3, during an interview at the Pentagon. “This is about preventing [Iran] from developing a nuclear weapon.”

Panetta clarified U.S. demands ahead of a second round of negotiations over Iran’s nuclear program, saying the Islamic Republic must “suspend any kind of nuclear enrichment” and “make no efforts to develop any kind of nuclear weapon.”

The United States has repeatedly called on Iran to comply with its U.N. Security Council obligations, recently demanding its “cessation of uranium enrichment and the verifiable decision by the regime…to forego pursuit of a nuclear weapon.”