Ukraine has hit a Russian chemical plant with Storm Shadow missiles, its military said on Tuesday, referring to the UK-made long-range weapon.

Calling the strike a successful hit that penetrated the Russian air defence system, Ukraine's general staff of the armed forces said they were still assessing the outcome of the massive strike.

The Kremlin has warned the West not to give Ukraine weapons capable of long-range attacks, but Kyiv says it's imperative to target Russian facilities that play a key role in Moscow's war against Ukraine.

The Bryansk Chemical Plant is a key facility of the aggressor state's military-industrial complex, the Ukrainian military said in an X post on Tuesday.

It added that the plant produces gunpowder, explosives and rocket fuel components used in ammunition and missiles employed by the enemy to shell the territory of Ukraine.

Moscow's authorities have not yet commented on the strike.

The attack came on the same day that UK Prime Minister Sir Keir Starmer and other European leaders vowed to ramp up the pressure on Russia's economy and its defence industry until Russian leader Vladimir Putin is ready to make peace.

A joint statement - co-signed by the Ukrainian, German, French, Italian, Polish, Danish, Finnish, EU and Norwegian leaders - added that Ukraine must be in the strongest position - before, during, and after any ceasefire.

Russia launched an overnight air attack on Ukraine's capital Kyiv on Wednesday morning, according to the city's mayor, Vitali Klitschko.

Witnesses heard explosions that sounded like air defence units in operation, the Reuters news agency reported.

The latest attacks came after a meeting at the White House last week between Donald Trump and Ukraine's President Volodymyr Zelensky, during which the US leader indicated he was not ready to supply sought-after Tomahawk cruise missiles to Kyiv.

Russia launched its full-scale invasion of Ukraine in February 2022. It currently controls about 20% of Ukrainian territory, including the southern Crimea peninsula Moscow annexed in 2014.