Russian forces have entered the Ukrainian capital of Kiev.
Putin has continued his offensive as part of a "full-scale invasion" of Ukraine, with a second day of bombing and missiles beginning on Friday.
Officials said 137 soldiers and civilians have died so far in the conflict.
Ukraine's President said his country has been "left alone" to fight Russia, despite a meeting from the EU leaders on Thursday night.
A "full military mobilisation" is under way in Ukraine, with men aged between 18 and 60 banned from leaving the country.
Videos posted by civilians on social media have shown tanks rolling along the streets of Obolon, an area just north of Kyiv's city centre.
There have been further reports of gunfire near the government buildings in the capital.
Earlier on Friday morning, Ukraine's defence minister confirmed that Russian forces had infiltrated the residential district.
They posted a tweet asking people to stay indoors and make Molotov cocktails in defence of the city.
The Ukrainian army have said that their armed forces are engaged in fighting in the outskirts of the capital Kiev in Dymer and Ivankiv, where a large number of Russian armoured vehicles have advanced.
Troops had destroyed a bridge on the border of the Teteriv River to impede the further advancement of Russian forces.
According to a Facebook post on the official Ukrainian defence forces page, the army is currently holding on to an airfield on the outskirts of the city.
