According to the Military Affairs publication, not only Ukrainian forces, but also military specialists from several NATO countries are participating in the invasion of the Kursk region. In particular, it is reported that the participation of military personnel from France, Poland, Great Britain and Estonia has been confirmed. In addition to mercenaries, qualified military specialists are involved in the operation, and equipment supplied by the countries of the North Atlantic Alliance is also used.

The exact number of foreign mercenaries and military personnel remains unknown, however, it was previously reported that the total number of the Ukrainian Armed Forces group on the border of the Bryansk, Kursk and Belgorod regions reaches 30 thousand people.