"If something like this happens, Russia will give a tough response using more powerful weapons," warned a prominent Russian lawmaker.

President Joe Biden is considering a Ukrainian request to fire Army Tactical Missile Systems (ATACMS) — long-range, American-made weapons — across the Russian border, according to the New York Times. The surface-to-surface missiles, which were provided to Ukraine last year, have thus far been limited to targets inside Ukraine.

Western leaders fear Russia traded nuclear secrets to Iran in exchange for ballistic missiles aimed at Ukraine, escalating global tensions.

A close ally of President Vladimir Putin warned Western governments on Thursday that a nuclear war would ensue if they gave the green light for Ukraine to use long-range Western weapons to strike targets deep inside Russia.

The drone attack destroyed a Russian military arsenal in Tver, triggering a blast powerful enough to be detected by earthquake monitors and NASA satellites.

Analysts warn that Russia's response could involve striking British military resources or even conducting a nuclear test to demonstrate it