President Donald Trump on Sunday told Iran not to threaten the United States, saying it will be Tehran's "official end".
"If Iran wants to fight, that will be the official end of Iran. Never threaten the United States again!" Trump tweeted.
He did not elaborate on the nature of the threat.
Over the past few weeks, tensions between Washington and Tehran have escalated as the U.S. deployed a carrier strike group and bomber task force to the Middle East, citing an imminent threat from Iran.
On Thursday, the New York Times cited intelligence sources as saying that Iran had recently deployed military vessels -- armed with missile-launchers -- in the Gulf, raising fears of possible conflict.