Swiss president Didier Burkhalter got a shock when Ukraine's interim prime minister Arseny Yatsenyuk greeted him in front of a Danish flag instead of the Swiss colours when they met for the first time in Kiev.
Burkhalter did not look happy with the diplomatic gaffe, as the picture above shows.
Twitter users made merry with the moment an embarrassed Yatsenyuk realised the wrong flag was being displayed.
Burkhalter was visiting Kiev to "underscore the constructive role played by the [Organisation for Security and Co-operation in Europe] in the Ukrainian crisis and the organisation's intention to step up its efforts to contribute to de-escalating the tensions in the country," according to Switzerland's Federal Department of Foreign Affairs.
He serves as the head of the OSCE and told Yatsenyuk that he intended to increase the number of international observers in Ukraine in response to Russian aggression in the east of the country.