LEESBURG, Virginia (Reuters) - Vice President Dick Cheney on Sunday described Iran as an obstacle to peace in the Middle East and said the world could not stand by and allow it to develop a nuclear weapon.

Cheney's comments underscored a ratcheting up of U.S. rhetoric toward Tehran and came just days after President George W. Bush warned that a nuclear-armed Iran could lead to World War Three.

"The Iranian regime needs to know that if it stays on its present course, the international community is prepared to impose serious consequences," Cheney told a forum organized by the Washington Institute for Near East Policy. "The United States joins other nations in sending a clear message: We will not allow Iran to have a nuclear weapon."

"Our country and the entire international community cannot stand by as a terror-supporting state fulfills its most aggressive ambitions," he said.