The European Parliament on Thursday adopted a resolution calling on EU countries to let Ukraine use Western weapons to strike military targets inside Russia, prompting an angry rebuke from Moscow.
Kyiv has been pleading with its allies to allow it to use donated arms to strike "legitimate" military targets deep in Russian territory, like the air bases used by Russian planes in their relentless bombardment of Ukraine.
EU lawmakers approved the resolution, which is non-binding and does not reflect the stance of the bloc's 27 countries, with 425 votes in favour, 131 against and 63 abstentions, during a plenary session in Strasbourg.
The text "calls on the member states to immediately lift restrictions on the use of Western weapons systems delivered to Ukraine against legitimate military targets on Russian territory."
The status quo "hinders Ukraine's ability to fully exercise its right to self-defence under international public law and leaves Ukraine exposed to attacks on its population and infrastructure," reads the resolution.
Echoing an earlier warning by President Vladimir Putin, Vyacheslav Volodin, the president of Russia's lower house Duma, condemned the vote, saying that Russia would give a "tough response" if the resolution were acted on.
"What the European Parliament is calling for leads to a world war using nuclear weapons," Volodin said, warning that Russian missiles could hit Strasbourg within minutes of launch.
On the Ukrainian side, Foreign Minister Andriy Sybiga welcomed the resolution which he said showed "decisiveness and leadership" from the European Parliament.
Kyiv wants more flexibility to hit Russian airfields and other military targets further from the front lines that it says are crucial to Moscow's invasion.
The United States and Britain have been discussing allowing it to do just that -- but EU states remain divided over the issue.
This month, Putin warned that green-lighting the use of long-range weapons deep inside Russia would put the NATO military alliance "at war" with Moscow.
Washington currently authorises Ukraine to only hit Russian targets in occupied parts of Ukraine and some in Russian border regions directly related to Moscow's combat operations.