New Delhi, Feb 25 : The International Atomic Energy Agency said it is following the situation in Ukraine 'with grave concern' and appealed for maximum restraint to avoid any action that may put Ukraine's nuclear facilities at risk, Daily Mail reported. Ukrainian presidential advisor Myhailo Podolyak said: "After the absolutely senseless attack of the Russians in this direction, it is impossible to say that the Chernobyl nuclear power plant is safe." It comes after Russian forces seized control of Chernobyl nuclear power plant after a 'fierce' battle, with the condition of nuclear storage facilities 'unknown', sparking fears of a radiation leak that could cause fallout in Europe, the report said. Video revealed Russian tanks and armoured vehicles standing in front of the destroyed reactor, which sits just 60 miles north of the capital Kyiv. An official said Russian shelling hit a radioactive waste repository and an increase in radiation levels was reported, although this has not yet been corroborated, Daily Mail reported. Speaking after the latest developments, US President Joe Biden announced more sanctions against Russia but admitted that he had not expected previous threats of financial penalties to deter Vladimir Putin. He also resisted calls to send in US troops to Ukraine, saying he has no plans to speak to the Russian leader who he accuses of trying to rebuild a Soviet empire. /IANS