He said the reactor the French took such a strong stance on "is ultimately to create the type of nuclear fuel for nuclear weapons."
Menendez said that there is a possibility that the Senate could push for new sanctions against Iran soon. He said he would like to see the sanctions include language that would end the punitive measure should a deal be reached.
"It's an insurance for the United States to make sure that Iran actually complies with an agreement that we would want to see," he said.
Menendez was skeptical of ongoing talks with Iran, and urged U.S. leaders to proceed with caution.
"My concern here is that we seem to want the deal almost more than the Iranians. And you can't want the deal more than the Iranians, especially when the Iranians are on the ropes," he said. "We have to be very wide-eyed as to what these negotiations are if we accept."