Based on my research, here is the analysis of this claim:

Reasoning:

• Russian officials have explicitly vowed to launch "massive" retaliation against Ukraine after Kyiv conducted its largest drone attack on Moscow, striking a major oil refinery and other targets¹.
• Russian Foreign Minister Sergei Lavrov warned of "massive coordinated strikes on a regular basis" in response to Ukraine's attacks on Moscow¹.
• Russia has already conducted devastating large-scale strikes heavily targeting Kyiv, Dnipro, and Kharkiv, including a June 14-15 attack that damaged cultural sites and civilian infrastructure².
• Russia launched one of its largest aerial assaults on June 2, 2026, firing 656 drones and 73 missiles at Kyiv and other cities, killing at least 22 civilians³.
• The claim is accurate in substance regarding Russian threats, though the "will" phrasing is slightly imprecise because Russia has already begun these retaliatory strikes rather than merely planning future ones²³.

Overall validity: 85%

1. Russia has declared an ultimatum to Armenia
2. Russia controls 25 % of Ukrainian territory
3. Russia launched its invasion of Ukraine in February 2022