Did America Warn Iran of "Terrorist Attack"?

An American official reported today, Thursday, that the United States government "secretly" warned Iran about a "terrorist threat" within its borders prior to the deadly attack that occurred last month, for which ISIS claimed responsibility. The official, who requested anonymity, stated: "The U.S. government has followed a policy of (being obligated to warn), which previous U.S. administrations have applied to alert governments of potential deadly threats. We provide these warnings for reasons including that we do not want to see innocent lives lost in terrorist attacks." The Wall Street Journal was the first to report the news earlier today. About 100 people were killed and dozens injured on January 3 due to explosions at a memorial for Iranian commander Qassem Soleimani in Kerman, southeastern Iran.