Ukraine and Russia: What you need to know right now

* Moldova's president said a series of attacks in the Russia-backed breakaway region of Transdniestria were an attempt by factions within the territory bordering on Ukraine to stoke tensions, and the Kremlin voiced serious concern. DIPLOMACY, SANCTIONS, AID * The United States said the world was galvanized against Russia's two-month-old invasion of Ukraine as it hosted defence talks in Germany involving over 40 countries that sought to speed and synchronize the delivery of arms to Kyiv.

The United States and its allies pledged new packages of ever heavier weapons for Ukraine during a meeting on Tuesday at a German air base, brushing off a threat from Moscow that their support for Kyiv could lead to nuclear war. SPILLOVER INTO MOLDOVA? * Moldova's president said a series of attacks in the Russia-backed breakaway region of Transdniestria were an attempt by factions within the territory bordering on Ukraine to stoke tensions, and the Kremlin voiced serious concern.

DIPLOMACY, SANCTIONS, AID * The United States said the world was galvanized against Russia's two-month-old invasion of Ukraine as it hosted defence talks in Germany involving over 40 countries that sought to speed and synchronize the delivery of arms to Kyiv. * United Nations Secretary-General Antonio Guterres told Russia's foreign minister on Tuesday he was ready to fully mobilise U.N. resources to save lives and evacuate people from the besieged Ukrainian city of Mariupol. * Germany announced on Tuesday its first delivery of heavy weapons - Gepard tanks with anti-aircraft guns - to Ukraine to help it fend off Russian attacks after weeks of pressure at home and abroad to do so amid confusion over its stance. FIGHTING

Reports of battlefield developments below could not be immediately verified by Reuters: * Ukraine's general staff said Russia's offensive continued in the eastern regions of Kharkiv and Donetsk, where it said they were taking "actions along almost the entire line of contact". * Russia is probably trying to encircle heavily fortified Ukrainian positions in the country's east, the British military said in an update on Tuesday, noting forces were trying to advance towards the cities of Sloviansk and Kramatorsk. * Russia's defence ministry said its missiles destroyed six facilities powering railways used to deliver foreign weapons to Ukrainian forces in the eastern Donbas region. HUMAN AND ECONOMIC IMPACT * Ukrainian farmers in the southern region of Zaporizhzhia that borders the frontline of the military conflict with Russia are now wearing body armour to plough their fields. Ukraine is the world's fifth-biggest exporter of wheat and in the top three for maize, barley and sunflower seeds. * Nuclear engineer Liudmyla Kozak was part-way through a 12-hour overnight shift at the defunct Chornobyl plant when Russia invaded Ukraine on Feb. 24 and workers heard explosions from the edge of the so-called exclusion zone around the site. What followed were the most dramatic events at the plant since the 1986 nuclear disaster there.

RUSSIAN WARNING * One of President Vladimir Putin's closest allies said on Tuesday that Ukraine was spiralling towards a collapse into several states because of what he cast as a U.S. attempt to use Kyiv to undermine Russia. QUOTES * "NATO, in essence, is engaged in a war with Russia through a proxy and is arming that proxy. War means war." - Russian Foreign Minister Sergei Lavrov * "Nations from around the world stand united in our resolve to support Ukraine in its fight against Russia's imperial aggression." - U.S. Defense Secretary Lloyd Austin (Editing by Angus MacSwan and Mark Heinrich)