U.S. Secretary of State Mike Pompeo on Saturday accused Iran of leading attacks on Saudi oil plants.

“Tehran is behind nearly 100 attacks on Saudi Arabia while Rouhani and Zarif pretend to engage in diplomacy. Amid all the calls for de-escalation, Iran has now launched an unprecedented attack on the world’s energy supply,” Pompeo said on Twitter .

“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.”

Yemen’s Iran-aligned Houthi group said it attacked two plants at the heart of Saudi Arabia’s oil industry on Saturday.

The attacks will cut the kingdom’s output by 5.7 million barrels per day, according to a statement from state-run oil company Saudi Aramco, or more than 5% of global oil supply.