U.S. forces struck three Iranian nuclear sites in a "very successful attack," President Donald Trump said on Saturday, adding that Tehran's nuclear program had been obliterated, Reuters reported.

After days of deliberation and long before his self-imposed two-week deadline, Trump's decision to join Israel's military campaign against its major rival Iran represents a major escalation of the conflict.

"The strikes were a spectacular military success," Trump said in a televised Oval Office address. "Iran's key nuclear enrichment facilities have been completely and totally obliterated."

In a speech that lasted just over three minutes, Trump said Iran's future held "either peace or tragedy," and that there were many other targets that could be hit by the U.S. military, according to Reuters.