apartment complexes have been hit in kyiv over the last 24 hours. more and more pictures we are seeing like this, civilians suffering. we're also awaiting an extraordinary summit of sorts from the leaders of three key nato nations. we're talking about poland, the czech republic and slovenia. they're all headed to kyiv at this moment to meet with ukrainian leader president zelenskyy there in the capital. a city under siege. clearly a huge risk in that. meantime, in southern ukraine, we have seen relentless attacks on this key port city of mykolaiv in the south, an effort by the russians to take over that key strategic port. cnn's nick paton walsh, we want to warn you, some of this video is graphic. >> reporter: we have seen during the night behind me the sky occasionally light up from the continued rocket fires that go back and forth between the two sides here as russia, it seems, is trying to move to the north