The move, the first time the U.S. has attacked Iran, is a major escalation of the conflict between Israel and Iran. U.S. involvement has divided Republicans, including Trump's closest allies.

The United States decisively entered into conflict with Iran on Saturday after President Donald Trump ordered US warplanes to drop massive bombs on three nuclear sites inside the country, thrusting him squarely into an escalating Middle East conflict even as he holds out hope the matter can be resolved diplomatically.

By Menna AlaaElDin, Pesha Magid and Maha El Dahan DUBAI/RIYADH (Reuters) -Gulf states, home to multiple U.S. military bases, were on high alert on Sunday after U.S. strikes on Iran raised the possibility of a widening conflict in the region.