Because of the sanctions against Russia, the train services were stopped, until the VR Group announced on 14 December 2023 that it would acquire the entire rolling stock of Allegro to itself from Russian Railways after Russian Railways had neglected its duty towards Karelian Trains.

After the Russian invasion of Ukraine in February 2022 and the subsequent international sanctions against Russia, services on the Allegro trains were stopped for the time being.

[9] Border inspections on the Allegro were performed while the train was on the move, as its passengers remained seated.

On board the inaugural service were Finnish president Tarja Halonen and Russian prime minister Vladimir Putin.

EU authorities asked VR to keep this train running so that those wishing to leave Russia could do so (though as part of COVID-19 restrictions, only Finnish and Russian citizens were allowed to use the train, and it ran only twice a day at half-capacity, of 327 passengers; but operators worked to lift those restrictions in order to allow the evacuation of other nationals).

[21] In December 2023, it was announced that VR Group had assumed the financial obligations of the joint stock company that used to run Allegro since it could no longer meet them itself.

[citation needed] On board the train, each passenger was visited by Finnish Border Guard and customs officers, as well as their Russian counterparts.

The Allegro service was operated using Class Sm6 electric multiple unit trainsets built by Alstom, with a top speed of 220 km/h (140 mph).