Iran summoned the Russian and British ambassadors on Thursday after a photograph was posted on the Russian embassy's Twitter account recalling the 1943 Tehran Conference, when Iran was occupied by the Allied powers, Iranian state media reported.
The picture, which outgoing foreign minister Mohammad Javad Zarif called "extremely inappropriate", has drawn criticism in Iran, with many saying on Twitter that the aim appeared to be to remind them of a time when their country was under foreign occupation.
It showed the Russian envoy, Levan Dzhagaryan, and Britain's ambassador, Simon Shercliff, sitting where U.S. president Franklin D. Roosevelt, British prime minister Winston Churchill and Soviet leader Joseph Stalin sat together at the Russian embassy during the 1943 strategy meeting.
Foreign minister-designate Hossein Amirabdollahian said it "showed disregard for diplomatic etiquette and the national pride of the Iranian people".
"During the meeting, the Russian ambassador stated that his intention to publish this photo was merely a reminder of Russia's alliance with Britain against the Nazi army during World War Two," Iran's foreign ministry said in a statement.
"There was no anti-Iranian motive behind the photo," the statement added, according to state TV.
While emphasising friendly relations between Iran and Russia, an Iranian foreign ministry official made clear that publication of the photograph "was not acceptable", the statement said.
The Russian embassy said it had no wish to cause offence.
"Taking into account the ambiguous reaction to our photo, we would like to note that it does not have any anti-Iranian context. We were not going to offend the feelings of the friendly Iranian people," it tweeted.
"The only meaning that this photo has to pay tribute to the joint efforts of the allied states against Nazism during the Second World War. Iran is our friend and neighbor, and we will continue to strengthen relations based on mutual respect" the Russian embassy added.
Shercliff retweeted the comments.
The semi-official Tasnim news agency said the British envoy "regretted the misunderstanding" over the picture and said that "there was no bad intention behind it".
Iranian authorities say they see Moscow as a "strategic partner" in talks between Tehran and six powers to revive a 2015 nuclear deal that Washington abandoned three years ago.
Tensions between Iran and Britain have risen over an attack last month on a tanker in which a Briton died. Britain blamed Tehran, which denied involvement.
