The Russian Federation has been increasing the number of troops deployed along the Ukrainian-Russian border.

"This concerns both the Kharkiv sector and areas closer to [Ukraine's strategic port city of] Mariupol. We see them deploying [their troops]," Deputy Commander of the Joint Forces Operation (JFO) Staff Major General Bohdan Bondar said on Hromadske.

According to him, this has gradually been happening during the entire war in Donbas.

"At first, let's say, their capabilities were limited. And since then, they've built both training ranges and facilities to accommodate military units and subunits, and expanded those components that had already existed," he said. "As the sector was not a priority to the Russian Federation, but now they have virtually rebuilt the railway, which no longer passes through the territory of Ukraine. That is, they've built military infrastructure able to transfer forces and equipment, including to certain areas, within a short period of time."

Read alsoRussia amassing troops along border with Ukraine – JFO Staff deputy commander

As UNIAN reported earlier, the Russian Federation has amassed a 30,000-strong military force in the temporarily occupied Crimea, planning to increase the contingent by another 7,000-10,000 by 2025, according to Vadym Skybytskiy, acting deputy commander of the Main Intelligence Directorate of the Ministry of Defense of Ukraine. Among other forces, Russia has deployed three air defense divisions equipped with S400 missiles.