(WASHINGTON) -- Even as Iranian missiles were streaking across the skies over Israel this week, U.S. officials say they were actively engaging with their Israeli counterparts to game out an appropriate response to the attack and underscore the need to avoid escalation.
Now that the fog of war has subsided to reveal that Iran's barrage on Tuesday did not incur massive loss of life or widespread damage, several Biden administration officials tell ABC News they're more optimistic they can persuade Israel to carry out a measured response -- but said they still fear a significant counterattack could trigger additional military action from Iran that leads to spiraling escalation in the Middle East.
One U.S. official said Israel aims to reestablish deterrence through its response by putting on a show of force. However, the official said Israel is unlikely to hit Iran's nuclear facilities -- a move that would spark ire from Tehran and one President Joe Biden made clear he does not support following a conversation with other members of the G7.
"We'll be discussing with Israelis what they're going to do," Biden said Wednesday. "All seven of us agree that they have a right to respond, but they should respond in proportion."
Another U.S. official said Israel could opt to go after other targets critical to Iran's economy, like the country's energy grid or its oil production infrastructure, but that striking a military installation would be the route with the lowest risk of escalation.
They added that the Biden administration believes Israel is still evaluating its options and has not yet set a firm timeline for its response.
An Israeli official told ABC News on Wednesday that its retaliation would be "significant" and "come fast."
The Iranian regime has issued a range of messages following Tuesday's attack on Israel, blaming the presence of the U.S. and some European nations in the Middle East for the turmoil in the region and declaring that peace depends on "rooting out the evil of these countries" while also declaring Tehran doesn't want a broader war.
"We don't seek war, it is Israel that is forcing us to react," Iranian President Masoud Pezeshkian said during a press conference in Qatar on Wednesday.
Tehran said its attack was incited by the assassination of Hamas' political leader Ismail Haniyeh on Iranian soil in July, which was widely attributed to Israel, and the killing of Hezbollah leader Hassan Nasrallah in an Israeli strike last week.
The Biden administration has lauded the killing of Nasrallah, saying Israel acted to bring the leader of a designated terror organization to justice. But the killing of the Iranian proxy group's leader has also complicated the leverage the U.S. has over Israel.
In April, Tehran launched a drone and missile attack at Israel to settle the score following an Israeli airstrike on an Iranian diplomatic compound in Damascus, Syria. Then, the tit-for-tat ended with a murmur -- a muted counterblow from Israel on a single Iranian military site.
But in the spring, Israel still wished to avoid provoking Hezbollah, making the country more amenable to the Biden administration's pleas for caution. Now, Israel is actively carrying out ground incursions into Lebanon and has greatly diminished the militant group's capability.
The Biden administration initially responded to Israel's actions in Lebanon by urgently calling for a cease-fire.
Now, U.S. officials say they are still pursuing a diplomatic solution, but the public messaging from Washington has pivoted back to one of support for Israel rather than calls for truce in Lebanon.
"Make no mistake, the United States is fully, fully supportive of Israel," Biden said.