With talks over Iran's nuclear program ongoing in Geneva, Secretary of State John Kerry today criticized Ayatollah Ali Hosseini Khamenei's comment that Israel is the "rabid dog" of the Middle East.

"Obviously we disagree with it profoundly … It's inflammatory, it's unnecessary, and I think at this moment when we are trying to negotiate what can and can't be achieved, the last thing we need is names back and forth," Kerry told the Senate Foreign Relations Committee.

Khamenei made the comment in a speech to Basij paramilitary members in Tehran on Wednesday, the Associated Press and others reported. Khamenei has empowered President Hassan Rouhani and Foreign Minister Javad Zarif to seek a deal with the U.S., Europe, Russia, and China that would roll back international economic sanctions. On Wednesday, he stressed limits to Iranian concessions.

Depending on how negotiations progress in Geneva, Kerry could fly there before talks are scheduled to end Friday.

"Obviously we don't believe that anything is served with, you know, names that challenge everybody's sense of propriety and justice and rectitude. We've been through this before, as we've heard prior, very disturbing assertions regarding the Holocaust," Kerry said. "We need to move away from this."

French President Francois Hollande has called the comment "unacceptable," the AP and the Times of Israel reported.