Israel views the dispatch of two Iranian warships to the Mediterranean with "gravity," Prime Minister Benjamin Netanyahu said on Sunday, as the vessels were expected to pass though the Suez Canal.
Egypt has given the two ships permission to cross the waterway en route to Syria, the first time Iranian warships will have done so since the Islamic revolution of 1979.
The planned passage has prompted criticism from Israel, with Foreign Minister Avigdor Lieberman calling it a "provocation."
During his weekly cabinet meeting on Sunday, Netanyahu said Israel viewed the ships' movement as an Iranian power play.
"Today we are witnessing the instability of the region in which we live and in which Iran is trying to profit by extending its influence by dispatching two warships to cross the Suez Canal," Netanyahu said, according to a statement released by his office.
"Israel views with gravity this Iranian initiative and other developments that reinforce what we have said in past years about Israel's security needs."
A senior Suez Canal official told AFP on Sunday that the Iranian warships had yet to reach the waterway, after an Iranian television earlier reported that the ships were already in the Mediterranean.
"No Iranian ships have passed. Not today, not yesterday, not the day before," the head of the canal's operations room, Ahmed al-Manakhly, told AFP by telephone.
Manakhly did not say when the Iranian ships were scheduled to arrive but canal officials have privately said they were expected early on Monday.
The Kharg has a crew of 250 and can carry up to three helicopters. The Alvand is armed with torpedos and anti-ship missiles.
Egypt's MENA news agency has reported that the request for the ships to pass through the Suez Canal said they were not carrying weapons, or nuclear or chemical materials.