After suffering some of the worst fighting in Ukraine's conflict, could the port city of Mariupol be about to fall to Russia? A brigade fighting in the city said they could be facing a "last battle" and that they would soon have to choose between Russian captivity and death. But the exact picture of what is happening in the city is unclear. Mariupol's deputy mayor called the reports "fake" and said Ukraine's forces were holding out. Mariupol's defence against Russian occupation has turned the city into a national symbol of resistance. The port city - which Russian forces have tried and failed to capture fully since the beginning of the war - is critical for Moscow as it would establish a land corridor between Russian-occupied Crimea and the Donbas region in eastern Ukraine. For weeks Russian troops have cut off essential supplies into Mariupol, bombarding its buildings and blocking survivors from escaping. The battle for Mariupol can be seen as part of Russia's shift in focus to eastern Ukraine. Here's how Russia's attack may play out. Responding to the news that the two Nordic neighbours could apply for Nato membership - Russia says any enlargement of the Western military alliance would not result in more stability. "Further [Nato] expansion will not bring additional security to the European continent," Kremlin spokesman Dmitry Peskov said to reporters. Russian's disapproval is no surprise: for decades Moscow has opposed any more European countries joining the alliance. But Russia's invasion of Ukraine has prompted Finland and Sweden to seriously consider asking for membership, which comes with security guarantees that Ukraine as a non-member didn't have. The face-to-face meeting is the first to have been held between a Western leader and President Putin since the invasion began. Austrian Chancellor Karl Nehammer says he went to the Russian capital to confront Putin with the facts, but didn't leave with a positive impression. "If you're asking me whether I am optimistic or pessimistic, I'm rather pessimistic," he said, adding there was "little interest" on the Russian side about a direct meting between Mr Putin and the Ukrainian president Volodymyr Zelensky. For his part, President Zelensky was asked whether he would hand over any part of Ukraine to Russia. He said he was "not ready" for that, but accepted it would be part of any discussion.