"Our intelligence experts are convinced that the attack targeted by the Israelis is in fact an atomic reactor of the same type built by North Korea in Yongbyon," she wrote in the message dated April 2008.
"We have good reason to believe that the reactor was not built for peaceful purposes," she said, adding the attack came only weeks before the reactor was to become operational.
Rice also noted the secrecy surrounding the construction of the nuclear facility, with the Syrian authorities refusing to invite the International Atomic Energy Agency or any media to inspect the site.
Syria has always denied that the structure targeted by Israeli warplanes was a nuclear reactor, although it has admitted it was a "military site under construction."
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