Speaking following a meeting of senior British ministers, chaired by Prime Minister Boris Johnson, to discuss the crisis, Raab said he had spoken to Iranian foreign minister Mohammad Javad Zarif earlier on Monday.
"The key message that we have got to all of our European and American partners but critically also to the Iranians, to the Iraqis and all of those affected in the region is the importance of defusing the tensions, to de-escalate ... and the importance of finding a diplomatic way through," Raab said.
Asked about President Donald Trump's threat to attack Iranian cultural sites, Raab said such sites were protected under international law and Britain expected that to be respected.