The US Secretary of State Mike Pompeo described attacks on Saudi oil facilities as an "act of war" by Iran. Tehran has denied a role in the attacks and said a military strike against Iran would end in "all-out war."
US Secretary of State Mike Pompeo said Thursday the US "stands with Saudi Arabia and supports its right to defend itself" after an attack on the kingdom's oil industry over the weekend.
Saudi Arabia and the United States blamed Iran for the assault, but Tehran denies any involvement. Saudi officials on Wednesday presented drone and missile wreckage, which they said proved Iran was responsible.
The incident has further escalated tensions in the region amid the collapse of Iran's 2015 nuclear deal with world powers and a series of confrontations in the Gulf.
'Act of war'
Pompeo called Saturday's drone and cruise missile attack on a vital oil processing facility "unprecedented" and an "act of war," adding that Iran's "threatening behavior would not be tolerated." He made the comments on Twitter following a meeting with Crown Prince Mohammed bin Salman in the Saudi city of Jeddah.
Saudi Arabia is the world's biggest exporter of oil, and the raids initially knocked out half of its output.
Strike against Iran would lead to 'all-out war'
When asked about the possibility of a military strike against Iran, the Saudi ambassador to Berlin told Germany's Deutschlandfunk radio that "all options are on the table."
Iranian Foreign Minister Mohammed Javad Zarif said on Thursday that the result of any US or Saudi military strike against his country would result in "all-out war."
"I am making a very serious statement that we don't want war; we don't want to engage in a military confrontation," Zarif told CNN. "But we won't blink to defend our territory."
Iranian-backed Houthi rebels fighting a Saudi-led coalition in Yemen said they were behind the oil facility strikes, but the US and Riyadh said Iran directly sponsored the attack. French Foreign Minister Jean-Yves Le Drian said Thursday that the Houthi claim "lacks credibility."
UAE joins US naval coalition
Pompeo was expected to travel to the United Arab Emirates on Thursday to meet with Abu Dhabi's crown prince, Sheikh Mohammed bin Zayed Al Nahyan.
His visit comes as the UAE announced it would join the US-led coalition formed to protect waterways in the Middle East.
State-run media quoted a Foreign Ministry spokesman as saying the UAE hoped to "ensure global energy security and the continued flow of energy supplies to the global economy."
Australia, Bahrain and the UK are already members of the maritime safety group, which was formed after a series of attacks on tankers in the region and aims to cover the Strait of Hormuz, Bab al-Mandab, the Sea of Oman and the Persian Gulf. Saudi Arabia signed up on Wednesday.
The UAE is a close Saudi ally and part of the coalition fighting the Houthis in Yemen.