In a tweet, Mr Pompeo said there was "no evidence" the drones came from Yemen.
"The United States will work with our partners and allies to ensure that energy markets remain well supplied and Iran is held accountable for its aggression", the top U.S. diplomat added.
President Donald Trump on Sunday telephoned Saudi Crown Prince Muhammad Bin Salman after attacks on two Saudi Aramco plants, including the world's biggest oil processing facility.
Saudi interior ministry spokesman Mansour al-Turki told AFP there were no casualties in the attacks in the kingdom's Eastern Province.
Texas girl, 10, dies after contracting rare brain-eating amoeba while swimming
About a week later, on September 8, Lily started suffering from a fever, according to NBC Dallas-Fort Worth. Texas' Department of State Health Services shared the following tips to reduce risk of infection.
The statement said the company is now working on restoring the lost quantities, and will present updated information within the next 48 hours. "The United States Government is monitoring the situation and remains committed to ensuring global oil markets are stable and well supplied", deputy White House press secretary Judd Deere said in a statement. Saudi authorities later said that the incident occurred due to a drone attack.
"We call on all nations to publicly and unequivocally condemn Iran's attacks", Pompeo said, warning that the Trump administration would work with its allies to make sure Iran was "held accountable for its aggression".
Riyadh has accused Iran and its proxies of being behind previous attacks on oil pumping stations and the Shaybah oilfield, charges Tehran denies.
The index's earlier gains were fuelled by Saudi Arabia's entry into the MSCI and FTSE Russell's emerging market indices.
The attack comes after U.S. President Donald Trump said a meeting with Iranian President Hassan Rouhani was possible at the United Nations General Assembly in NY this month.
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A business owner showed a reporter a crack in a cinder-block building near the site of the blast . Janet Mills confirmed that a firefighter died in the incident on Monday, Sept. 16.
Saudi Arabia's Crown Prince Mohammad emphasized the country's "willingness and strength to thwart such a terrorist aggression and deal with its consequences", according to a statement carried by state news agencies.
Aramco is not only the world's biggest oil producer, it is also one of the world's most profitable businesses. "The Iran conflict is going to be hitting the world in a new way", said Kevin Book, managing director, research at ClearView Energy Partners LLC.
The country produces 10 percent of the world's crude oil. The Rapidan Energy Group, a Washington-based advisory group, warned in May that "a successful attack could lead to a monthslong disruption of most Saudi production and almost all spare production".
Iran today dismissed as "meaningless" United States accusations it was behind drone attacks on Saudi oil installations, suggesting Washington was seeking a pretext to retaliate against the Islamic republic.
Attention, les prix du carburant vont augmenter !
La semaine dernière le prix des carburants a déjà augmenté en France, avec un litre de gazole vendu en moyenne 1,4298 euro. Avec la mondialisation, ce qui se passe au Moyen-Orient peut avoir de fortes répercussions chez nous.