Ukraine travel warning issued for Americans as Russian troops mass on border

Ukraine signs security deal with Sweden in push for Western support

Germany, Sweden pledge new aid for Ukraine

Sky's security and defence analyst, Professor Michael Clarke gives an update on the latest troop movements in Ukraine.

Ukrainian President Zelenskyy confirmed there are "dead and wounded" as a result of the strikes on the capital.

Russia has targeted Ukraine's capital Kyiv and the nuclear station Zaporizhzhia but what other key resources are vulnerable?