Over the weekend, Iran began moving moving missile launchers and conducting military drills, US officials told the Wall Street Journal.
According to the officials, such activities could indicate that Iran is preparing to attack Israel in the coming days.
WSJ also noted that the Biden administration is concerned that an Iranian attack may be accompanied by an attack by Hezbollah and other Iranian proxies, in an attempt to overwhelm Israel's defenses.
Security sources told the Lebanese Al Anbaa newspaper that they estimate that Hezbollah will attack Israel in the coming days, and next week at the latest.
At the same time, the front page of the Hezbollah-affiliated Al Akhbar newspaper featured a picture of Tel Aviv, with the headline reading, "Whether it happens earlier or later, the punishment will come."
Hezbollah leader Hassan Nasrallah is expected to speak Tuesday at 5:00p.m., one week after the terror group's second-in-command, Fuad Shukr, was confirmed eliminated in a strike.
Shortly after Shukr's death, Hamas leader Ismail Haniyeh was killed in Tehran.
Israel took responsibility for Shukr's death, but has not commented on Haniyeh's.