Iran on Sunday denied US claims that it was behind the drone attacks on oil facilities that knocked out half of Saudi Arabia’s output even as a top commander in the Revolutionary Guard threatened to strike American bases in the Middle East with ballistic missiles.

Brig. Gen. Amir Ali Hajizadeh in an interview published on state-run media said Revolutionary Guard forces were prepared to retaliate if the US responds militarily and laid out as targets bases in Qatar and the United Arab Emirates as well as Navy ships in the Persian Gulf and Arabian Sea.

“Wherever they are, it only takes one spark and we hit their vessels, their airbases, their troops,” Hajizadeh said.

His heated rhetoric comes as Sen. Lindsey Graham wrote a Twitter post calling for the US to punish Iran for the drone attacks on the Saudi installations.

“It is now time for the U.S. to put on the table an attack on Iranian oil refineries if they continue their provocations or increase nuclear enrichment,” the South Carolina Republican said.

Counselor to the President Kellyanne Conway said the administration will “keep many options on the table” but wouldn’t rule out whether President Trump and Iranian President Hassan Rouhani will meet this month at the United Nations General Assembly to discuss sanctions and the 2015 nuclear deal.

“I’ll allow the president to announce a meeting or a non-meeting,” Conway said on “Fox News Sunday.”

But she repeated Secretary of State Mike Pompeo’s accusations that Tehran was behind the attack and said: “You’re not helping your case much.”

Rep. Adam Schiff (D-Calif.) blamed the heightened tensions in the region on Trump’s decision last year to withdraw from the nuclear deal but added the president should continue to pursue a diplomatic solution.

“We do need to get back to diplomacy and there are openings to do so; there are voices within Iran, unusual voices, including arch-conservatives suggesting it’s time to start talking to the United States again. The U.S. should seize that opportunity,” he said on CBS’ “Face the Nation.”

Leaders of the Iranian-backed Houthi rebel group claim they launched drones from Yemen 500 miles into Saudi Arabia as part of a coordinated attack on the Abqaiq refinery – the world’s largest – and the Khurais oil field early Saturday morning.

Pompeo on Saturday said “there is no evidence the attacks came from Yemen” and blamed Iran for launching “an unprecedented attack on the world’s energy supply.”

Iranian Foreign Ministry spokesman Abbas Mousavi called the remarks “blind and futile comments.””The Americans adopted the ‘maximum pressure’ policy against Iran, which, due to its failure, is leaning towards ‘maximum lies,'” Mousavi said in a statement.

Saudi Aramco, the state-owned oil company that operates the facilities, said the attacks interrupted about 5.7 million barrels of crude, which represents about 5 percent of the world’s daily production.

The Saudi Foreign Ministry said the drop in output would be made up by tapping stockpiles.

The US and its allies accuse Iran of providing weapons and support to the Houthi insurgents in Yemen as they battle Saudi-coalition forces that have destroyed whole cities and left thousands dead.

Washington has been supplying the Saudis with advanced arms and technology.

Trump on Saturday spoke with Saudi Crown Prince Mohammed bin Salman to offer support.

The tense relationship between Iran and the US has been escalating since Trump withdrew from the 2015 nuclear accord and reimposed punishing sanctions on the country as part of a “maximum pressure” campaign.

Iranian Foreign Minister Javad Zarif blasted Pompeo’s remarks, saying he’s turning to “max deceit” because the “max pressure” campaign is failing.

“US & its clients are stuck in Yemen because of illusion that weapon superiority will lead to military victory,” he wrote on Twitter. “Blaming Iran won’t end disaster. Accepting our April ’15 proposal to end war & begin talks may.”