There was a Russian Cossack choir, a horse-drawn carriage and a venue specialising in a Viennese fried chicken. But one thing about the wedding of the Austrian foreign minister, Karin Kneissl, stood out: among the guests was the Russian president, Vladimir Putin.

The exact details of Putin’s controversial “private” visit weren’t confirmed until the last minute, when his private plane touched down at the tiny Graz regional airport early yesterday afternoon. The airport was briefly closed to passengers and sealed off by a large police presence supported by Austria’s elite Cobra taskforce.

A Cossack choir serenades Austrian foreign minister Karin Kneissl and her groom Wolfgang Meilinger at their wedding. Photograph: ROLAND SCHLAGER / POOL/EPA

Putin’s party then travelled in a convoy of black vans to the Tscheppe restaurant, known for its Backhendl chicken, and boasting a terrace overlooking a mountain vineyard in the picturesque Alpine state of Styria.

Television pictures showed Kneissl, 53, who had arrived earlier together with her groom, businessman Wolfgang Meilinger, accepting a bunch of flowers from Putin at the gate. And the two politicians then shared a dance – witnessed by the only photographer granted access to the ceremony.

Putin’s entourage included the choir, which serenaded the couple and their guests, among them Austrian chancellor Sebastian Kurz of the conservative Austrian People’s party and vice chancellor Heinz-Christian Strache from the far-right Freedom party (FPÖ). The Russian president left a short time afterwards, rushing off to Berlin for wide-ranging bilateral talks with German chancellor Angela Merkel.

Kneissl, an independent, owes her appointment as foreign minister to the populist, anti-immigrant FPÖ, the junior party in Austria’s ruling coalition. A polyglot who speaks seven languages including Arabic and Hebrew, she was previously known as a journalist and Middle East analyst who made frequent appearances on Austrian broadcaster ORF and in recent years shifted to the right.

Putin’s attendance at her wedding drew anger from opponents who said it undermined the EU’s stance against Russia over Ukraine. For Kneissl to invite “the most aggressive foreign adversary of the EU” to a private celebration was “completely unacceptable”, Austrian Green MEP Michel Reimon said last week, calling for her resignation.

Kneissl’s display of warmth to Putin also prompted outrage in Kiev, and sparked calls for Austria to withdraw from the EU Commission’s efforts to mediate an end to the frozen conflict with Russian-backed separatists in the country’s east.

“It goes without saying: if you invite Vladimir Putin to your wedding, you are not neutral any more,” tweeted Ukrainian MP and foreign affairs committee member Hanna Hopko. “From now on, Austria can’t be a mediator in Ukraine. Period.”

In a later Facebook post Hopko demanded Russia be held to account for the Skripal nerve agent attack in the UK, the downing of Malaysian Airlines flight MH17 and alleged war crimes in Aleppo, Syria.

The Austrian government said Putin attended as “a personal guest”. Foreign ministry spokesman Matthias Forenbacher said: “No change will result in terms of Austria’s foreign policy position.”

Kneissl first met the Russian president 17 years ago at a summit in Slovenia with the then US President George Bush in July 2001. A self-proclaimed “conservative free spirit,” she belongs to no party and has proved a divisive figure since her appointment to Austria’s rightwing coalition cabinet last December.

Kneissl’s scepticism over Austria’s acceptance of refugees from the Middle East won applause from the FPÖ and gained her the foreign ministry when the populists rose to power last December. Kneissl has sharply criticised the EU’s handling of Brexit and Catalonia’s drive for independence and poured scorn on Angela Merkel’s open-door migration policy, which she has called “grossly negligent”.

Putin’s attendance at the wedding could be taken as a slight in Berlin, where Merkel had dampened expectations for Saturday’s “working meeting,” the first time the leaders had met since a fractious summit in Sochi in May.