US President Donald Trump initially projected the war to last four to five weeks, but since sought to justify a broad, open-ended war on Iran.
Netanyahu rejected the idea of the conflict lasting years, like previous wars in the region.
"I said it could be quick and decisive. It may take some time, but it's not going to take years. It's not an endless war," Netanyahu said on Fox News on Monday.
As the war entered its fourth day on Tuesday, explosions shook buildings across Tel Aviv as air defences intercepted incoming Iranian missiles.
Israel attacked the complex that houses Iran's state broadcaster IRIB in Tehran and targeted Hezbollah militants in towns across Lebanon.
Early on Tuesday, two drones, apparently from Iran, struck the US embassy in Riyadh, causing minor damage and starting a fire, and at least eight more drones were intercepted before reaching the city, Saudi Arabia's Defence Ministry said.
The Islamic Revolutionary Guard Corps said its naval forces had destroyed the main command building and headquarters of a US airbase in Bahrain in what it described as the 14th wave of "Operation Promise of the Truth 4".
The IRGC said in a statement it had launched a large-scale drone and missile attack on the base in the Sheikh Isa area early in the morning, with 20 drones and three missiles striking their intended targets.
The US State Department and the White House did not immediately respond to requests for comment.
US Secretary of State Marco Rubio on Monday warned "the hardest hits are yet to come from the US military" in the offensive against Iran.
Asked how long he expected the United States to be engaged in Iran, Rubio told reporters he did not know, and he did not rule out the possibility Trump might deploy US troops to fight a ground war in the Middle East.
"We believe the objectives we have set for this mission, the destruction of their ballistic missile capabilities, both launch capabilities and manufacturing can be achieved without ground forces," Rubio said.
"Right now we are not postured for ground forces. But obviously the president has those options and he is not going to rule out anything."
The US and Israeli air war against Iran began with attacks against Tehran on Saturday, which killed Iranian Supreme Leader Ali Khamenei.
Retaliation from Iran and its proxy Hezbollah has dragged the wider Gulf region into the conflict, killing hundreds of civilians in Iran, Israel and Lebanon.
The US military said it had struck more than 1250 targets in Iran and destroyed 11 Iranian ships. Six US service personnel have been killed so far, all in Iran's retaliatory attacks over the weekend on Kuwait.
Kuwait mistakenly shot down three American F-15E fighter jets during an Iranian attack, US Central Command said. All six crew members ejected and were safely recovered.
The conflict has thrown global air transport into chaos and shut down shipping through the Strait of Hormuz, where one-fifth of the world's oil trade skirts the Iranian coast, sending oil prices surging.
Major Gulf hubs, including the world's busiest international airport Dubai, which usually handles over 1000 flights a day, remained closed for a fourth day due to the conflict.
That has left tens of thousands of passengers stranded as aviation faced its biggest test since the COVID-19 pandemic.
Asian airline shares extended losses on Tuesday, with carriers closely monitoring fuel price spikes and many seeing a surge in bookings as passengers switch from Middle Eastern airlines.
Global oil and gas shipping rates soared, with supertanker costs in the Middle East hitting all-time highs, after Tehran targeted ships passing through the Strait of Hormuz, according to shipping data and industry sources on Tuesday.
Trump has said the US faced an imminent threat from Iran justified the war, although he gave no specifics and some US lawmakers said he has shown no evidence to back that assessment.
US Secretary of State Marco Rubio told reporters on Monday the United States acted pre-emptively because it knew of close ally Israel's plan to strike Iran and knew Tehran would respond, putting US bases at risk.
Trump on Monday said he had ordered the attack to thwart Tehran's nuclear program and a ballistic missile program that he said was growing rapidly.
Trump's assault on Iran is the biggest US foreign policy gamble in decades and a major political risk for his Republican Party in this year's midterm elections, with only one in four Americans saying they support the Iran attack, according to a weekend Reuters/Ipsos poll.
