Russia showed no letup in pounding Ukrainian cities already large reduced to rubble but still in their defenders’ hands. But Western defence analysts suggested Russian troops were becoming demoralised and had lost some ground to Ukrainian forces

President Joe Biden, due to attend summits in Europe this week of NATO, the European Union and the G7, said the stiff resistance of Ukrainian offenders three weeks into the Kremlin’s invasion had put Kremlin leader Vladimir Putin’s "back against the wall”.

Officials in Mariupol, where residents have been subject to bombardments and without power, water and heat, said fighting had engulfed districts where Russian troops had broken through defences.

Western defence analysts suggested Russian troops were bogged down, particularly outside the capital, the invaders’ supply lines unable to provide troops with food and fuel. One U.S. estimate said the Russian death toll stood at 7,000 troops.

Veteran Russian Foreign Minister Sergei Lavrov said some progress had been made, particularly in establishing Ukraine as a neutral country. But Kremlin leader Vladimir Putin said Moscow would not be deflected from the aims of its military campaign, while U.S. President Joe Biden described Putin as a war criminal.

Ukrainian President Volodymyr Zelensky acknowledged that his ex-Soviet state had no chance of becoming a member of NATO at least for some time.

The 160 carloads of residents able to make their way out of Mariupol were among some 4,000 evacuees escaping bombardments in cities besieged by the Russian military since Kremlin leader Vladimir Putin launched an invasion of Ukraine on 24th February.

Ukrainian officials said some 140,000 people had been evacuated from cities under threat from Russian attack, but no such operation has yet been launched in the besieged southern port of Mariupol owing to constant shelling. The death toll in the city was put at 2,100.

The punitive measures are wide-ranging: they will target Russia’s officials, businessmen, as well as the country’s banking, technology and key industrial sectors.

More than 12,000 residents were evacuated from several towns, but not from Mariupol, surrounded for more than a week, its residents deprived of heating, water and running dangerously low on food.