Russia has given the most sombre assessment so far of its invasion of Ukraine, describing the “tragedy” of mounting troop losses and the economic hit from sanctions, as Ukrainians were evacuated from eastern cities before an anticipated major offensive.

Moscow’s six-week long incursion has led more than four million people to flee abroad, killed or injured thousands, turned cities into rubble and led to sweeping sanctions on Russian leaders and companies.

In a symbolic move, the United Nations General Assembly suspended Russia from the UN Human Rights Council early on Friday (Australian time), expressing “grave concern at the ongoing human rights and humanitarian crisis”.

Russia then quit the council.

Moscow has previously acknowledged its attack has not progressed as quickly as it wanted. On Friday, Kremlin spokesman Dmitry Peskov lamented the rising death toll.

“We have significant losses of troops,” he told Sky News.

“It’s a huge tragedy for us.”

Russia faced its most difficult economic situation for three decades due to unprecedented Western sanctions, Prime Minister Mikhail Mishustin said. The US Congress has removed its “most favoured nation” trade status, in a further blow.

Russia launched what it calls a “special military operation” on February 24 to demilitarise and “denazify” Ukraine. Kyiv and its Western allies reject that as a false pretext.

Following new restrictions after the killing of civilians in the town of Bucha that were widely condemned by the West as war crimes, Ukraine called on allies to stop buying Russian oil and gas, amid divisions in Europe, and to boost it militarily.

“Ukraine needs weapons which will give it the means to win on the battlefield and that will be the strongest possible sanction against Russia,” President Volodymyr Zelensky said in a video late on Thursday.

He also said the situation in Borodyanka – another town north-west of Kyiv retaken from Russian forces – was “significantly more dreadful” than in Bucha, without citing any evidence.

Video from Borodyanka showed search and rescue teams using heavy equipment to dig through the rubble of a building that collapsed. Hundreds of people were feared buried.

Moscow has denied targeting civilians and says images of bodies in Bucha were staged to justify more sanctions and derail peace negotiations.

The EU’s ambassadors have agreed on a fifth sanctions package on Russia. It includes a coal embargo that features a 120 day wind-down period to give member states time to find alternative suppliers, following pressure from Germany to delay the measure.

On the battlefield, Ukraine said after withdrawing from Kyiv’s outskirts, Russia was regrouping to try to gain full control over the eastern regions of Donetsk and Luhansk, which have been partly held by Russian-backed separatists since 2014.

The besieged southern port of Mariupol, where the mayor said more than 100,000 people were still trapped, was also a target.

Both sides continued to trade accusations, with Moscow opening a criminal investigation into a Russian soldier’s allegations that he was beaten and threatened with death while being held in Ukraine as a prisoner of war.

Separately, a social media video verified by Reuters and geolocated to an area west of Kyiv appears to show Ukrainian forces shooting and killing a captured and badly wounded Russian soldier.

NATO members agreed to strengthen support to Ukraine on Thursday.

Ukraine has received about 25,000 anti-aircraft weapons systems from the US and its allies, the top US general said, and Washington is looking into what new support it could send.

Bushmasters were loaded on to an RAAF plane at Brisbane’s Amberley base on Friday. Photo: ADF

In Queensland, the first of 20 Bushmaster armoured vehicles, which include two ambulance variants, worth $50 million were loaded on planes on Friday for flights to Ukraine.

Prime Minister Scott Morrison said Australia would also send a further $26.5 million in military aid for Ukraine in the form of anti-armour weapons and ammunition.

In the US, the Biden administration said it had committed more than 12,000 anti-armour systems, 1400 anti-aircraft systems and “hundreds” of suicide drones to Ukraine. The latest promise brings the total US assistance to Ukraine to approximately $US1.7 billion ($2.3 billion) since the beginning of Russia’s invasion.

It followed a plea a video address posted on YouTube from Ukrainian Defence Minister Oleksii Reznikov for heavier, more modern weapons as Russia concentrated its forces for a powerful attack.

Russia had “drawn conclusions and changed tactics” and was focusing on long-range strikes from the air.

As a result, Ukraine needs air defence systems, long-range artillery, tanks and anti-ship missiles, Reznikov said.

Zelenskiy’s government says starving Moscow’s war machine is the only way to bring it to a settlement at on-and-off peace talks.

On Thursday, Russian Foreign Minister Sergei Lavrov said a draft peace deal from Kyiv contained “unacceptable” elements and deviated from previously agreed proposals.

-with AAP