Russian President Vladimir Putin on June 5 said Moscow could supply advanced weapons to certain regions to enable strikes against "sensitive" Western targets as a response if Ukraine strikes Russia with Western arms.
Recently, the U.S. and Germany partially lifted a ban on Ukraine using certain weapons supplied by them to strike Russian territory.
Responding to a journalist's question on the matter during a meeting with the world's leading news agencies in St. Petersburg, Putin promised Russian air defenses would intercept these arms and that Moscow would respond in kind.
"What should we do in response? Firstly, of course, we will improve our air defense systems; we will destroy them," Putin said.
"Secondly, we think that if somebody considers supplying such weapons to a combat zone to strike our territory... then why don't we have the right to supply comparable weapons to regions where they could be used to strike sensitive targets of countries that do this to Russia?"
The Russian leader, who launched the largest full-scale war in Europe since World War II, also said that such an action would "completely destroy international relations" and "undermine international security."
Putin reiterated threats that Western countries could be "drawn into the war against Russia" and that such a step would mean their "direct participation in the war."
The Kremlin has repeatedly issued both veiled and overt threats to Kyiv's partners over their support for Ukraine, including threats of a nuclear response.
Washington and Berlin, Kyiv's leading military donors, were long hesitant to permit Ukraine to use American and German arms to target Russian territory, fearing an escalation with Moscow.
Their positions shifted after Russia launched a new offensive in the north of Kharkiv Oblast in early May. Ukrainian forces complained that these restrictions prevented them from effectively striking Russian forces amassing at the border.
American and German officials clarified that the ban was lifted on striking Russian military targets near border areas, namely in the area of Kharkiv. The U.S. kept restrictions on striking deep inside Russia with long-range arms like ATACMS in place.
A number of other countries said they apply no restrictions on how Ukraine uses foreign-supplied arms.
The Associated Press (AP) reported on June 5 on a supposedly first strike with the U.S.-supplied weapons inside Russia, which allegedly took place in "recent days."