New Delhi, Feb 25 (IANS): Ukraine's leader has said a "new iron curtain" is falling and closing Russia off from the "civilised world" after it invaded its neighbour, BBC reported.

President Volodymyr Zelensky said Ukraine's task was "for that curtain not to fall" on its territory.

He made the remarks as Russian forces attacked on several fronts, launching missile strikes and advancing towards the capital Kyiv, the report said.

Exact casualty numbers are unclear, but include Ukrainian civilians.

Zelensky made his comments in a video address to the Ukrainian people in which he swapped his usual suit for a military uniform, BBC reported.

"What we have heard today are not just missile blasts, fighting and the rumble of aircraft. This is the sound of a new iron curtain, which has come down and is closing Russia off from the civilised world," he said.

The iron curtain refers to the division between Europe's communist east and capitalist west from the end of the Second World War to the end of the Cold War.

Russia's invasion by land, air and sea began after a pre-dawn TV address where President Vladimir Putin demanded that Ukraine's military lay down its arms. It followed weeks of escalating tensions, as Russia massed troops along Ukraine's borders, the report said.