Ukraine and Russia: What you need to know right now

Ukraine acknowledged difficulties in fighting in its east as Russian forces regrouped after stepping up pressure and making advances on two cities ahead of an EU summit this week expected to welcome Kyiv's bid to join the bloc.

Ukraine acknowledged difficulties in fighting in its east as Russian forces regrouped after stepping up the pressure and making advances on two cities ahead of an EU summit this week expected to welcome Kyiv's bid to join the bloc. FIGHTING * Serhiy Gaidai, the governor of Ukraine's Luhansk region, scene of the heaviest Russian onslaughts in recent weeks, said a relatively quiet Monday night signaled "a calm before the storm" after a massive Russian attack and advances. * Ukrainian President Volodymyr Zelenskiy had predicted Moscow would escalate attacks ahead of the EU summit on Thursday and Friday. He was defiant in a late Monday address despite "difficult" fighting in Luhansk for Sievierodonetsk and Lysychansk. * A Russian missile destroyed a food warehouse in the Ukrainian Black Sea port of Odesa after the Russia-installed leader of the annexed Crimea peninsula said Ukrainian forces had attacked drilling platforms owned by a Crimean oil and gas company. * Reuters could not independently verify battlefield reports.

PRISONERS * The Kremlin said Americans captured in Ukraine were "mercenaries" who had shot at Russian servicemen and were not covered by the Geneva convention, RIA reported, quoting Kremlin spokesman Dmitry Peskov as saying they should take responsibility for their "crimes". * RIA also quoted the Kremlin as saying that American star basketball player Brittney Griner, who has been detained in Russia since February, faces criminal prosecution. Russia has previously said it had detained her for possession of vape cartridges containing hash oil. ECONOMIC AND SECURITY REPERCUSSIONS * At a summit on Thursday and Friday, European Union leaders are expected to give their blessing to Ukraine becoming an official candidate to join. * Russia warned NATO member Lithuania that unless it quickly lifts a new ban on the transit of goods to Russia's Kaliningrad exclave on the Baltic Sea, then Moscow will take undisclosed measures to defend its national interests. * Europe's biggest Russian gas buyers are racing to find alternative fuel supplies and even looking at burning more coal to cope with reduced gas flows from Russia that threatens an energy crisis in winter if stores are not refilled.