President Donald Trump said the United States is "locked and loaded" after an attack on Saudi Arabia's oil supply, but his administration is waiting on Riyadh to determine who launched the strikes before proceeding on a course of action.
"There is reason to believe that we know the culprit, are locked and loaded depending on verification," Trump said in a post on Twitter.
Trump said he authorized the release of oil from the U.S. strategic petroleum reserve to keep the market well supplied.
Attacks crippled the heart of Saudi oil production over the weekend, hitting the world's largest crude processing facility and the kingdom's second-largest oilfield. Aramco, Saudi's national oil company, was forced to cut production by 5.7 million barrels per day or about 50%. That is equivalent to about 5% of the global oil supply.
Oil futures spiked after the weekend attack. U.S. West Texas Intermediate crude futures popped $6.4, or 11.67%, to $61.23 per barrel. Brent crude futures jumped $7.89, or 13.3% to $68.07.
Yemen's Houthi rebels claimed responsibility for the attack, but the U.S. has pointed the finger at Iran. Secretary of State Mike Pompeo accused Tehran of launching an "unprecedented attack on the world's energy supply."
Iran has dismissed those allegations as "meaningless," "not comprehensible" and "pointless."
Foreign Minister Javad Zarif called on the Trump administration to hold talks. But Trump tweeted on Sunday saying: "The Fake News is saying that I am willing to meet with Iran, 'No Conditions.' That is an incorrect statement (as usual!)."
Tensions between the U.S. and Iran have escalated significantly since Trump pulled out of an international agreement that aimed to keep Tehran from developing a nuclear weapon. Trump thought the deal wasn't tough enough and has slapped sanctions back on the Islamic Republic.
Trump came close to launching military strikes against Iran in June after the Islamic Republic shot down a U.S. drone. The president said he called off those strikes over concern about the loss of life they would cause. Four weeks later, Trump said the U.S. navy destroyed an Iranian drone, though Tehran denied that was the case.
Washington has also accused Iran of attacking and seizing oil tankers in the Persian Gulf, allegations Tehran rejects.