The US has told at least one US ally in the Middle East, that they have intelligence showing that the launch was “likely” coming from staging grounds in Iran, but they have not shared that intelligence yet. “It is one thing to tell us, it is another thing to show us,” said a diplomat from the region.

A US official separately tells CNN that the US has assessed that the attack originated from inside Iran. The official spoke on condition of anonymity.

No public evidence has been shared.

What countries in the region decide to do, in reaction to the Saudi oil field attack, largely depends on what the US is willing to do, the source said. CNN reported earlier that Secretary of State is expected to speak with the UAE Crown Prince on Monday and other nations.

The Pentagon declined to comment. The State Department and the White House did not respond to a request for comment.

The WSJ first reported that the US was telling countries region that the attacks were launched inside Iran.

More context: The attack on oil facilities in Saudi Arabia likely involved cruise missiles and attack drones, a separate US official familiar with the intelligence assessment told CNN earlier today. The official said that the attacks did not originate from Iraq but would not say whether they originated from Iran or Yemen. Iraq's Prime Minister issued a statement Monday saying that Secretary of State Mike Pompeo had told him that the attacks had not originated from Iraq. The State Department when asked about the call, said “no comment.”

The US maintains an enhanced awareness of the airspace over Iraq given US military operations there as part of the counter-ISIS coalition.

While the Iran-backed Houthis in Yemen have used attack drones in the past, those attacks have typically been launched against Saudi targets close to the border.

The recent attacks against the Saudi oil facilities would represent a major improvement in the Houthis ability to accurately hit targets at a much greater distance than previously demonstrated.