US Secretary of State Mike Pompeo said Thursday that Iran was trying to raise the price of oil when it allegedly attacked oil tankers off the coast of the United Arab Emirates.

Pompeo’s remarks came a day after John Bolton, President Donald Trump’s national security advisor, said in Abu Dhabi that Iran was “almost certainly” behind the May 12 sabotage of four ships including two tankers from Iran’s arch-rival Saudi Arabia.

“Yes, Ambassador Bolton got it right. These were efforts by the Iranians to raise the price of crude oil throughout the world,” Pompeo told reporters as he left Washington for Berlin on a tour of Europe.

The United States is seeking to end of Iran’s sales of oil, its key export, as part of a campaign to fight back against Tehran’s regional role.

Iran strongly rejected Bolton’s accusations, saying the veteran hawkish official was among “warmongers” with “evil desires for chaos in the region.”

The accusations came as Saudi Arabia held emergency Arab and Gulf summits at which it tried to rally the world to a hard line on Iran.

The United States has sent nuclear-capable bombers and an aircraft carrier strike group to the region as it alleged imminent threats from the Islamic republic.

But Trump has said he does not war and that he is open to dialogue with Tehran.