More than 50,000 people have fled Ukraine since the start of the Russian invasion, the United Nations refugee chief said Friday.

Russian President Vladimir Putin called on the Ukrainian military to seize power in their country on Friday, a day after Moscow launched an invasion of its southern neighbour.

Ukraine's Defence Ministry said on Friday that more than 1,000 Russian servicemen had been killed so far in the Ukrainian conflict.

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".

Turkey cannot stop Russian warships accessing the Black Sea via its straits, as Ukraine has requested, due to a clause in an international pact that allows vessels to return to their home base, the Turkish foreign minister said on Friday.

Over the three decades since the fall of Soviet Union and the economic chaos that followed in Russia, many of those who became rich needed a safe heaven for their new-found wealth, and London became just that.

International Criminal Court (ICC) prosecutor Karim Khan on Friday expressed his concern over the Russian invasion of Ukraine and said his court may investigate possible war crimes in the country.

Ukraine's nuclear agency and interior ministry said on Friday they were recording increased radiation levels from the site of the defunct Chernobyl nuclear power plant.

Russia wants the Ukrainian people to be independent and have the possibility to freely define their destiny, Russian Foreign Minister Sergei Lavrov said on Friday.

Missiles pounded Kyiv on Friday and families cowered in bomb shelters as Russian forces pressed their advance and authorities said they were girding for an assault aimed at overthrowing the government.

Ukraine wants peace and is ready for talks with Russia, including on neutral status regarding NATO, Ukrainian presidential advisor Mykhailo Podolyak told Reuters on Friday.

Russia has banned British airlines from landing at its airports or crossing its airspace, its state civil aviation regulator said on Friday.

Russian and Ukrainian forces fought on Thursday for control of Chernobyl, the still radioactive site of the world's worst nuclear accident and a factor in the collapse of the Soviet Union.

Ukrainian forces battled Russian invaders on three sides on Thursday after Moscow mounted an assault by land, sea and air in the biggest attack on a European state since World War Two.

Russian President Vladimir Putin launched a ‘full-scale invasion’ of Ukraine yesterday, killing dozens and forcing thousands to flee for their lives in the pro-Western neighbour.

The prayers of the entire world are with the people of Ukraine tonight as they suffer an unprovoked and unjustified attack by Russian military forces. … The world will hold Russia accountable.

Satellite imagery shows a new build-up of Russian troops on the border with Ukraine, and Kyiv says Moscow has mobilised 100,000 soldiers along with tanks and other military hardware.

Russia has begun a large-scale military attack on Ukraine, its southern neighbour, on the orders of Russian President Vladimir Putin. There are reports of attacks on Ukrainian military infrastructure across the country, and Russian convoys entering from all directions. Here is what we know so far:

A son wept over the body of his father among the wreckage of a missile strike in a residential district in the eastern Ukrainian town of Chuguiv as the country reeled yesterday from Russia’s invasion.

Russia launched a wide-ranging attack on Ukraine on Thursday, hitting cities and bases with airstrikes or shelling, as civilians piled into trains and cars to flee. Ukraine’s government said Russian tanks and troops rolled across the border in a “full-scale war” that could rewrite the geopolitical order and whose fallout already reverberated around the world.