The Press Association
Israel has repeatedly warned that it believes Iran is pursuing nuclear weapons.
In his address, Sarkozy said Israel was not alone. He said the entire European Union was concerned about Iran's nuclear programme.
He said if Iran developed nuclear weapons, it would be unacceptable to France.
Sarkozy had previously urged a diplomatic solution that would prevent what he called the "catastrophe" of either an Iranian bomb or an attack on Iran.
The EU is expected to announce sanctions against Iran's biggest bank.
The move is aimed at stepping up international pressure on Tehran to bring its nuclear programme in line with international demands.
