OXFORD, Mississippi (CNN) - Iranian nuclear weapons would be an "existential threat to the state of Israel" and would encourage other countries in the Middle East to seek nuclear weapons as well, Sen. John McCain said Friday at his first presidential debate against Sen. Barack Obama.
"We cannot allow another Holocaust," he said.
Obama agreed that the United States "cannot tolerate a nuclear Iran," calling for tougher sanctions from a range of countries including Russia and China.
McCain called for a new "league of democracies" to stand firm against Iran.
He blasted Obama for being willing to meet "without preconditions" with Iranian President Mahmoud Ahmadinejad, who has repeated threatened Israel.
But Obama defended his stance, saying: "I reserve the right as president of the United States to meet with anyone at the time and place of my choosing if I think it's going to keep the American people safe."