Israeli officials confirmed Tuesday morning that the White House believes Iran is preparing an imminent missile attack on Israel.
But the IDF says it has not seen any activity that would indicate an attack is about to take place.
IDF spokesman Daniel Hagar warned that if Iran chooses to attack it would "have consequences."
Iran has been expected to retaliate after Hamas leader Ismail Haniyeh was assassinated in Tehran in July.
Israel has been fighting Iran-funded Hezbollah in Lebanon and Hamas is Gaza, wiping out much of its leadership.
The Israeli military said early Tuesday that troops have started "ground raids" in villages in southern Lebanon after militant group Hezbollah said it had targeted "enemy soldiers" at the countries' border.
Despite international calls for de-escalation, Israel earlier vowed to keep fighting Hezbollah and sealed part of the border after killing the Iran-backed group's leader.
The military said troops backed by airstrikes and artillery launched ground raids "a few hours ago" targeting militant group Hezbollah "in villages close to the border".
President Joe Biden on Monday voiced opposition to an Israeli ground operation.
"We should have a ceasefire now," he said.
The U.S. is sending thousands of additional troops to the region.
The AFP contributed to this report.
