Russian Foreign Minister Sergei Lavrov said Friday Moscow was ready for talks if Ukraine's military surrendered, as he insisted that invading forces were looking to free the country from "oppression".

Russian President Vladimir Putin "took the decision to conduct a special military operation to demilitarise and de-Nazify Ukraine so that, freed from oppression, Ukrainians themselves could freely determine their future", Lavrov said at a press conference in Moscow.

The comment suggested that Moscow intends to overthrow the Ukrainian authorities with its invasion.

Lavrov said Moscow was ready for talks with Kyiv if the Ukrainian army surrenders.

"We are ready for negotiations at any moment, as soon as the armed forces of Ukraine respond to our call and lay down their arms," Lavrov said.

He said the aim of Putin's operation was "openly declared: demilitarisation and de-Nazification".

Lavrov said that "nobody intends to occupy Ukraine".

He denied Ukrainian claims that Russian forces had hit civilian infrastructure, despite widespread evidence of residential areas being damaged.

The Ukrainian army said Friday that Russian forces were approaching Kyiv from the north and northeast.

Russian President Vladimir Putin announced he was launching a major military operation in Ukraine in the early hours of Thursday.

Western countries have imposed a barrage of international sanctions against Russia since then.