Ukraine and Russia: What you need to know right now

Russian President Vladimir Putin on Tuesday defended the war in Ukraine as a "noble" mission that would achieve its goals as his troops massed for a new offensive amid allegations of rape, brutality against civilians, and possible use of chemical weapons. FIGHTING

* Fighting in eastern Ukraine will intensify over the next two to three weeks as Russia continues to refocus its efforts there, the UK's Ministry of Defence tweeted in a regular bulletin on Tuesday. * Russian-backed separatist forces did not use chemical weapons in their attempts to take full control of Mariupol despite Ukrainian allegations to the contrary, Eduard Basurin, a separatist commander, told the Interfax news agency.

DIPLOMACY * Putin warned the West that attempts to isolate Moscow would fail, citing the success of the Soviet space program as evidence that Russia could achieve spectacular leaps forward in tough conditions.

* Putin said Russia's main aims of its "special military operation" were to protect the Russian-speaking people of Donbas in eastern Ukraine and to end Ukraine's position as a center of nationalistic anti-Russian feeling. * All options would be on the table in how the West responds to any use of chemical weapons in Ukraine by Russia, British armed forces minister James Heappey said on Tuesday.

CIVILIAN TOLL * Tens of thousands of people have likely been killed in Russia's assault on Mariupol, President Volodymyr Zelenskiy told South Korea's parliament.

ECONOMY AND BUSINESS * Russia's economy is on track to contract by more than 10% in 2022, the biggest fall in the gross domestic product since the years following the 1991 fall of the Soviet Union, former finance minister Alexei Kudrin said on Tuesday.

Russia is facing soaring inflation and capital flight while grappling with a possible debt default after the West imposed crippling sanctions to punish Putin for sending tens of thousands of troops to Ukraine on Feb. 24. * Zelenskiy urged the European Union on Tuesday to impose sanctions on all Russian banks and Russian oil and to set a deadline for ending imports of Russian gas.

* Russian state-owned gas producer Gazprom continued to supply natural gas to Europe via Ukraine on Tuesday at the pace of 74.6 million cubic meters per day, in accordance with requests from European consumers, the company said. * The World Bank is preparing a $1.5 billion support package for Ukraine, including a $1 billion payment from the development lender's fund for the poorest countries, World Bank President David Malpass said on Tuesday.

QUOTES * "I would like to remind world leaders that the possible use of chemical weapons by the Russian military has already been discussed. And already at that time, it meant that it was necessary to react to the Russian aggression much harsher and faster," said Zelenskiy.

* "We are seriously concerned about the possibility of the use of nuclear weapons during Russia's invasion of Ukraine," Japanese Chief Cabinet Secretary Hirokazu Matsuno told a news conference. "We, as a sole country that has suffered nuclear attacks during war, intend to keep on appealing firmly that any threat of the use of nuclear weapons, let alone their actual use, should never be allowed."