The Russian and Western nuclear industries remain dependent on each other, a situation that has shielded Russia from European sanctions, an industry report said on Thursday.

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.

Ukrainian drones hit an ammunition depot inside Russia this week, the latest attack targeting military facilities deep within the country.

Ukraine said it destroyed a large weapons stockpile in Russia overnight using long-range drones to stage the attack as Kyiv awaits US permission to use western-made missiles in such operations.

A senior Russian lawmaker on Thursday said that Ukrainian strikes on Russia with Western missiles would lead to global war with the use of nuclear weapons and that Moscow's response would be tough with more powerful weapons.

A Ukrainian drone attack on a Russian missile facility early Wednesday threw up towering fireballs visible from space and thundering detonations that triggered earthquake monitors.

A source in the Security Service of Ukraine said drones attacked a large weapons warehouse in Russia overnight.

A large-scale Ukrainian drone attack on Russia triggered an earthquake-sized blast at a major arsenal in the Tver region on Wednesday, forcing the evacuation of a nearby town, war bloggers and some media reported.