WASHINGTON (Reuters) - The United States is considering increasing its intelligence sharing with Saudi Arabia after Saturday’s attack on Saudi oil facilities, which halved the kingdom’s production and jolted world oil markets, U.S. officials told Reuters.

Smoke is seen following a fire at an Aramco factory in Abqaiq, Saudi Arabia, September 14, 2019. REUTERS/Stringer

The U.S. officials, who spoke on condition of anonymity, did not say how broad any increase in intelligence sharing might be or discuss other options being weighed by the administration as a response to the attack on the world’s biggest crude oil processing plant.

But the United States, long wary of deep involvement in the war in Yemen, has only selectively shared intelligence with Saudi Arabia about the threats from Yemen’s Iran-aligned Houthi militants, who claimed responsibility for the attack.

Such intelligence shared with the Saudis has long lacked the kind of detail that would allow the Saudi-led coalition to pinpoint Houthi leaders or their networks, which the United States has long maintained are supported by Iran.

Any expansion in U.S. intelligence sharing could trigger a sharp reaction from Congress, where lawmakers, outraged over civilian casualties in the war, have made several failed attempts to halt U.S. support to the Saudi-led coalition fighting in Yemen.

They have also tried to prevent President Donald Trump from selling more arms to the kingdom without congressional approval.

Trump has said the United States was “locked and loaded” to retaliate and on Monday questioned Iran’s claim that it had nothing to do with Saturday’s attack.

IRAN LINK

For, months Iranian officials have issued veiled threats, saying that if Tehran is blocked from exporting oil, other countries will not be able to do so either.

However, Iran has denied any role in a series of attacks in recent months, including bombings of tankers in the Gulf and the strikes claimed by the Houthis. The latest attack triggered the biggest surge in oil prices since 1991.

Iran’s Yemeni allies have promised more strikes to come. Houthi military spokesman Yahya Sarea said the group carried out Saturday’s pre-dawn attack with drones, including some powered by jet engines.

But several U.S. officials say they believe that the attack on Saudi Arabia came from the opposite direction, possibly from Iran itself rather than Yemen.

On Sunday, one U.S. official said: “There’s no doubt that Iran is responsible for this. No matter how you slice it, there’s no escaping it. There’s no other candidate.”

The war in Yemen, where the Saudis and the United Arab Emirates lead an air campaign against Iran-backed Houthi rebels, is considered one of the world’s worst humanitarian disasters.