Gulf states are lobbying Washington to stop Israel from attacking Iran's oil sites because they are concerned their own oil facilities could come under fire from Tehran's proxies if the conflict escalates, three Gulf sources told Reuters.

As part of their attempts to avoid being caught in the crossfire, Gulf states, including Saudi Arabia, the United Arab Emirates, and Qatar, are also refusing to let Israel fly over their airspace for any attack on Iran and have conveyed this to Washington, the three sources close to government circles said.

Israel has promised Iran will pay for its missile attack last week while Tehran has said any retaliation would be met with vast destruction, raising fears of a wider war in the region that could suck in the United States.

During meetings this week, Iran warned Saudi Arabia it could not guarantee the safety of the Gulf kingdom's oil facilities if Israel were given any assistance in carrying out an attack, a senior Iranian official and an Iranian diplomat told Reuters.

Ali Shihabi, a Saudi analyst close to the Saudi royal court, said: "The Iranians have stated: 'If the Gulf states open up their airspace to Israel, that would be an act of war'."

The diplomat said Tehran had sent a clear message to Riyadh that its allies in countries such as Iraq or Yemen might respond if there was any regional support for Israel against Iran.

A potential Israeli strike was the focus of talks on Wednesday between Saudi de facto ruler, Crown Prince Mohammed bin Salman, and Iranian Foreign Minister Abbas Araqchi, who was on a Gulf tour to rally support, Gulf and Iranian sources said.

Jonathan Panikoff, former deputy US national intelligence officer on the Middle East and now at the Atlantic Council think-tank in Washington said: "Gulf states' anxiety is likely to be a key talking point with Israeli counterparts in trying to convince Israel to undertake a carefully calibrated response."

The Organization of Petroleum Exporting Countries, which is de-facto led by Saudi Arabia, has enough spare oil capacity to make up for any loss of Iranian supply if an Israeli retaliation knocked out some of the country's facilities.

But much of that spare capacity is in the Gulf region so if oil facilities in Saudi Arabia or the UAE, for example, were targeted too, the world could face an oil supply problem.

"The Gulf states aren't letting Israel use their airspace. They won't allow Israeli missiles to pass through, and there's also a hope that they won't strike the oil facilities," the Gulf source said.

The three Gulf sources emphasized that Israel could route strikes through Jordan or Iraq, but using Saudi, UAE, or Qatari airspace was off the table and strategically unnecessary.

Analysts also pointed out that Israel has other options, including mid-air refueling capabilities that would enable its jets to fly down the Red Sea into the Indian Ocean, proceed to the Gulf and then fly back.