(Bloomberg) -- U.K. Prime Minister Boris Johnson said Iran was behind this month’s attack on Saudi Arabia’s key oil facilities.

“The U.K. is attributing responsibility with a very high degree of probability to Iran for the Aramco attacks,” Johnson told reporters traveling with him to New York for the United Nations General Assembly. “We think it very likely indeed” that Iran was responsible, and used both drones and cruise missiles, he added.

Johnson’s statement, based on an assessment by British intelligence agencies, brings the U.K. into line with the U.S. The prime minister is also expected to meet Iranian President Hassan Rouhani at the UN.

A U.K. official, speaking on condition of anonymity, said imagery from the site of the attack showed the remnants of Iranian-made land-attack cruise missiles. The official said that the scale, sophistication and range of the operation pointed to Iran and that it was implausible that it would have happened without the authorization of the Iranian government.

Britain is now considering how to respond, something that Johnson said was a “difficulty.” He said he hoped to act as a “bridge” between the U.S. and Europe to “construct a response that tries to deescalate tensions in the Gulf region.”

Nevertheless, Johnson said he was open to the possibility of increasing military deployment to the region.

“The Americans are proposing to do more to help to defend Saudi Arabia, and we will be following that very closely,” he said. “If we are asked either by the Saudis or by the Americans to have a role, then we will consider all the different ways we could be useful.”

To contact the reporter on this story: Robert Hutton in New York at rhutton1@bloomberg.net

To contact the editors responsible for this story: Tim Ross at tross54@bloomberg.net, Linus Chua, Virginia Van Natta

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