Ukraine and Russia: What you need to know right now

* Russia's defence ministry said on Saturday Ukrainian forces were retreating toward the city of Lysychansk after suffering "critical losses" of up to 90% in some units during fighting for nearby Sievierodonetsk.

Kyiv was rocked by several explosions early on Sunday, the mayor of the Ukrainian capital said, a day after officials said troops had recaptured a swathe of the battlefield city of Sievierodonetsk in a counteroffensive against Russia. FIGHTING * Russia hit Kyiv with cruise missiles fired from the Caspian Sea, striking a rail car repair facility in the Ukrainian capital, in the first such attack for weeks, Ukraine's army and railway chief said. * Ukrainian forces have counterattacked in Sievierodonetsk in the east of the country, Britain's defence ministry said. * Luhansk regional Governor Serhiy Gaidai said Ukraine now controls about half of Sievierodonetsk. * Russia's defence ministry said on Saturday Ukrainian forces were retreating toward the city of Lysychansk after suffering "critical losses" of up to 90% in some units during fighting for nearby Sievierodonetsk. * A Russian state media journalist on Sunday said that Russian Major General Roman Kutuzov had been killed in eastern Ukraine, adding to the string of high-ranking military casualties sustained by Moscow. * Ukraine's state-run nuclear power operator Energoatom said a Russian cruise missile flew "critically low" on Sunday morning over a major nuclear power plant. * Reuters could not independently verify battlefield reports.

WEAPONS AND DIPLOMACY * President Vladimir Putin warned the United States in an interview that Russia would strike new targets if the West supplied longer-range missiles to Ukraine for use in high-precision mobile rocket systems. * Spain is to supply Ukraine with anti-aircraft missiles and Leopard battle tanks in a step-up of its military support to the country, according to government sources quoted by El Pais newspaper. * Austrian Chancellor Karl Nehammer called for an intermediate stage between cooperation and full membership of the European Union for countries like Ukraine and Moldova. * Ukraine rebuked France's President Emmanuel Macron on Saturday for saying it was important not to "humiliate" Russia, a position Ukrainian Foreign Minister Dmitro Kuleba said "can only humiliate France". ECONOMY * Russia's sanctions against Gazprom Germania and its subsidiaries could cost German taxpayers and gas users an extra 5 billion euros ($5.4 billion) a year to pay for replacement gas, the Welt am Sonntag weekly reported, citing industry representatives. * Russian Foreign Minister Sergei Lavrov said on Saturday Western sanctions would have no effect on the country's oil exports, predicting a big jump in profits from energy shipments this year.

QUOTE * "The terrible consequences of this war can be stopped at any moment... if one person in Moscow simply gives the order," Ukrainian President Volodymyr Zelenskiy said, in apparent reference to Putin. (Compiled by William Mallard, Frances Kerry and Lisa Shumaker)