A former British General says he expects the conflict to reach the streets of Kiev in the next 24 to 48 hours.
Richard Barrons served tours in Bosnia, Northern Ireland, Iraq and Afghanistan, before being promoted to brigadier in 2003 and then Commander of the Joint Forces Command for three years between 2013-2016.
Ukrainian armed forces are in a battle to hold Kyiv - as Russian forces attempt to move in on the capital, it's understood tanks, infantry and heavy artillery are now just a few miles from the centre.
Ukraine's president says his forces are still in control of the capital and is appealing to the country's "friends" abroad to join the fight.
Volodymyr Zelenskyy appeared in a social media video earlier to counter claims he'd taken up an American offer to evacuate, as Russian forces descend on the city.
"Probably, the Russian objective is to have their tanks outside the Presidential Palace and in other key places around the city" Barrons explained to Sky News.
"So for the Russians, they won't just drive in. They're faced with fighting their way into a modern European city, and they're going have to answer the questions: how much of this city are they going to destroy? And how many civilians are they going to kill in order to claim that they've liberated it?
"For the defenders, the dilemma is reverse. They could stand outside the city, where they'll be easy targets for Russian artillery and tanks, or they could draw the Russians into the city, and that will become a much harder, much more dispersed fight, where Russian artillery will be less useful.
"And we will see this unfold in the next 24 to 48 hours."
