Ukraine and Russia: What you need to know right now

(Reuters) - Ukrainian forces have been ordered to withdraw from the key battleground city of Sievierodonetsk after weeks of fierce street fighting, in order to limit more casualties and regroup, but the move will be seen by Russia as a significant victory.

FIGHTING

* Ukraine officials said troops in Sievierodonetsk ordered to withdraw, very little left to defend in the bombed-out eastern city, where hundreds of civilians remain trapped in a chemical plant.

* Sievierodonetsk's twin Lysychansk to become the next main focus of fighting. Pro-Russian leader says it would take another week and a half to secure full control of Lysychansk.

* South of Sievierodonetsk, Ukrainian soldiers retreat from the towns of Hirske and Zolote in the face of overwhelming Russian forces, said Oleksiy Arestovych, an adviser to Ukrainian President Volodymyr Zelenskiy.

* Ukraine's foreign minister says retreating does not mean losing war, notes Russia had wanted to occupy eastern Donbas region by May 9.

* Ukraine's general staff said its troops had some success in the southern Kherson region, forcing the Russians back from defensive positions near the village of Olhine, the latest of several Ukrainian counter-assaults.

* Reuters was unable to independently verify the situation on the ground.

ECONOMY AND DIPLOMACY

* European Union leaders formally accepted Ukraine as a candidate to join the EU, a bold geopolitical move triggered by Russia's invasion of Ukraine.

* Russia says EU candidacy decision amounted to EU "enslaving" neighbouring countries.

* The G7 rich democracies will seek to show long-term support for Ukraine at a summit starting on Sunday, even as the war's growing impact on the world economy tests their resolve.

TRIALS

* Ukraine held a preliminary hearing in its first trial of a Russian soldier charged with raping a Ukrainian woman during Russia's invasion, the first of what prosecutors say could be dozens of such cases.

QUOTES

* "Remaining in positions smashed to pieces over many monthsjust for the sake of staying there does not make sense," Luhansk regional governor Serhiy Gaidai said on Ukrainian television.

(Compiled by Michael Perry; Editing by Sam Holmes)