Ukraine appealed again to allies on Monday for "extraordinary and bold steps" to supply air defences to help defend against waves of Russian air strikes that have targeted the energy system in recent weeks.

Russian missile and drone attacks have pounded Ukrainian energy infrastructure since mid-March, prompting Kyiv to issue increasingly desperate calls for air defence help.

"We urgently require additional Patriot and other modern air defence systems, weapons and ammunition," Foreign Minister Dmytro Kuleba told a Black Sea security conference via video link. "I take this opportunity to once again urge all of our partners to take extraordinary and bold steps."

"Ukrainian air defence is now protecting not only Ukrainian skies from Russian air terror, it also shields neighbouring Moldova, Romania and Poland from the immediate threat of missiles and drones entering their air space," he added.

The minister said on Sunday negotiations were ongoing for more Patriot systems for Ukraine, but decried their slow pace. (Reporting by Anastasiia Malenko; Editing by Tom Balmforth and Andrew Cawthorne)