(NewsNation) — Russian President Vladimir Putin warned in an interview broadcast Sunday that Moscow would strike new targets if the U.S. supplied long-range missiles to Ukraine.

“If it now comes to rockets and they are supplied, we will draw conclusions from that and employ our weapons that we have in sufficient quantities to strike those facilities that we are not attacking so far,” Putin stated on the Rossiya-1 TV channel, according to Russian state news agency Tass.

The threat of a military escalation from the Russian leader didn’t specify what the new targets might be, but it comes days after Biden administration’s decision to send a small number of high-tech, medium-range rocket systems, a critical weapon that Ukrainian leaders have been begging for as they struggle to stall Russian progress in the eastern Donbas region.

The United States has ruled out sending its own, or NATO, forces to Ukraine. Still, Washington and its European allies have supplied weapons to Kyiv such as drones and howitzer heavy artillery, as well as anti-aircraft Stinger and anti-tank Javelin missiles.

The rocket systems are part of a new $700 million tranche of security assistance for Ukraine from the U.S. that will include helicopters, Javelin anti-tank weapon systems, tactical vehicles, spare parts and more, according to two senior administration officials. The officials spoke on the condition of anonymity to preview the weapons package that is expected to be formally unveiled Wednesday.

The U.S. decision to provide the advanced rocket systems tries to strike a balance between the desire to help Ukraine battle ferocious Russian artillery barrages while not providing arms that could allow Ukraine to hit targets deep inside Russia and trigger an escalation in the war.

The Pentagon said last week it will take at least three weeks to get the precision U.S. weapons onto the battlefield.

Military analysts say Russia is hoping to overrun Ukraine’s embattled eastern industrial Donbas region, where Russia-backed separatists have fought the Ukrainian government since 2014, before any U.S. weapons that might turn the tide arrive.

In the television interview, Putin lashed out at Western deliveries of weapons to Ukraine, saying they aim to prolong the conflict.

“In my view, all this fuss over additional deliveries of armaments generally pursues the sole objective of stretching out the armed conflict as long as possible,” Putin said.

Putin’s warning comes as Russian airstrikes have hit the Ukrainian capital of Kyiv for the first time in weeks, sending up plumes of black smoke. Russia claims the airstrikes destroyed tanks donated from abroad. 

In a posting on the Telegram app, the Russian Defense Ministry said high-precision, long-range air-launched missiles were used. It said the strikes on the outskirts of Kyiv destroyed T-72 tanks supplied by Eastern European countries and other armored vehicles located in buildings of a train car repair business.

But the head of Ukraine’s railway system rejected the claim that tanks were inside. Oleksandr Kamyshin said four missiles hit the Darnytsia car repair plant, but no military equipment has been stored there. 

Nuclear plant operator Energoatom said one cruise missile buzzed close to the Pivdennoukrainsk nuclear plant, 350 kilometers to the south, and warned of the possibility of a nuclear catastrophe if even one missile fragment hit the plant.

Before Sunday’s early-morning attack, Kyiv hadn’t faced any such Russian air strikes since the April 28 visit of U.N. Secretary-General António Guterres. The attack triggered air raid alarms and showed that Russia still had the capability and willingness to hit at Ukraine’s heart, despite refocusing its efforts to capture Ukrainian territory in the east.

In the Azov Sea port of Mariupol, which Russia claimed to have captured in May after a monthslong siege, a mayoral aide said water supplies contaminated by decomposing corpses and garbage were causing dysentery and posing a threat of cholera and other diseases. In remarks carried by Ukraine’s Unian news agency, Petro Andriushchenko said Russian authorities controlling the city have imposed a quarantine. His report could not be independently confirmed.

Ukrainian President Volodymyr Zelenskyy traveled to the Zaporizhzhia region in the southeast, which is partly under Russian control. He received a battle report, thanked troops and met with refugees in what was only his second public visit outside the Kyiv area since the war began.

In more news of shipments of weapons to Ukraine, the Spanish daily El Pais reported that Spain planned to supply anti-aircraft missiles and up to 40 Leopard 2 A4 battle tanks to Ukraine. Spain’s Ministry of Defense did not comment on the report.

The Hill and the Associated Press contributed to this report.