The White House condemned “in the strongest terms” the attack on the British Embassy in Tehran on Tuesday and urged Iran to prosecute the offenders.

“Iran has a responsibility to protect the diplomatic missions present in its country and the personnel stationed at them,” White House Press Secretary Jay Carney said in a written statement. “We urge Iran to fully respect its international obligations, to condemn the incident, to prosecute the offenders, and to ensure that no further such incidents take place either at the British Embassy or any other mission in Iran.”

Iranian protesters stormed the British Embassy, ransacking the offices and vandalizing the property. Britain’s Foreign Office called the assault “utterly unacceptable” and advised British nationals in Iran to stay indoors and “keep a low profile.”

The White House said that the U.S. State Department is in close contact with the British government. “We stand ready to support our allies at this difficult time,” Carney said.