Russia's defence minister has inspected troops in frontline regions in eastern Ukraine, after the United States offered more support to Kyiv whose forces are struggling in Bakhmut.

Sergei Shoigu inspected an advance command post in the direction of the south of the Donetsk region, the defence ministry said, without specifying exactly where or when.

It put out a rare video of the Russian defence minister travelling in a helicopter and talking to a soldier in front of damaged buildings.

Shoigu handed state awards to servicemen and held a meeting with his deputies "on organising the uninterrupted provision of troops with armaments, military hardware and ordnance", his ministry later said.

The visit came with fierce fighting ongoing around Bakhmut, the longest battle of the conflict, which has further exposed rivalries between the conventional army and the Wagner paramilitary group.

Wagner chef Yevgeny Prigozhin said Friday his fighters had "practically encircled" Bakhmut.

Well-versed in social media, Prigozhin has for weeks been publicising the advances of his men towards the eastern city, whose symbolic importance outstrips any military significance.

Prigozhin regularly posts videos of himself alongside mercenaries, on the ground or even in a fighter jet, in contrast with Russian generals criticised for shirking the frontline.

In his latest video Friday, Prigozhin directly called on Ukrainian President Volodymyr Zelensky to abandon Bakhmut, which Russia is determined to seize as part of the wider aim of capturing the entire Donetsk region.

- Allies support -

Zelensky has pledged to defend "fortress Bakhmut" for as long as possible, calling on allies to intensify their support to help his men do so.

On Saturday the president of the European Parliament Roberta Metsola visited Ukraine, where she met Zelensky and called for the country to be allowed to begin its EU membership negotiations this year.

"The task is to actively prepare everything for our country's EU membership, increase the supply of weapons to Ukraine, and strengthen sanctions against Russia," Zelensky said in his daily address after the meeting.

US President Joe Biden on Friday hosted German Chancellor Olaf Scholz for his first visit since the offensive, a display of partnership after friction over supplying tanks to Ukraine.

Ahead of the meeting, the Kremlin warned that Western weapon deliveries to Kyiv would only "prolong the conflict and have sad consequences for the Ukrainian people".

The United States responded by offering another $400 million in security assistance.

The new security package features ammunition -- including for the HIMARS precision rocket system that Ukrainian forces have used to devastating effect against Russian troops and supply dumps.

Ukraine's Defence Minister Oleksiy Reznikov praised the package as "a solid investment in the future success of the Ukrainian army on the battlefield", where Western military aid has been key to Kyiv's ability to hold out and to even regain ground.

- 'Intense fighting' -

In the east however, Zelensky and several Ukrainian officials recognised an increasingly difficult situation around Bakhmut this week.

Sergiy Cherevaty, a spokesman for Ukrainian forces, said the situation was "difficult but under control" in the city he described as a "priority target for the enemy".

Ukraine's general staff update said on Saturday evening that its forces had repelled Russian troops "unsuccessfully trying to encircle the town of Bakhmut".

The British defence ministry's intelligence update on Saturday however said Ukraine was "under increasingly severe pressure, with intense fighting taking place in and around the city".

It added that "Ukrainian-held resupply routes out of the town are increasingly limited" and Wagner's troops and the Russian military had advanced in the northern suburbs of the city, which was now "vulnerable to Russian attacks on three sides".

The intelligence update also said that two key bridges in the town had been destroyed, including a vital bridge connecting the city to the last main supply route from Bakhmut to the city of Chasiv Yar.

While the epicentre of the fighting is in the east of Ukraine, the death toll from a strike this week on an apartment block in southern Zaporizhzhia has now risen to 11.

Moscow says its regions bordering Ukraine are routinely shelled by Ukrainian forces, but on Thursday it reported a rare instance of fighting inside Russia.

Russian security services said a group of Ukrainian combatants had crossed into the southern Bryansk region and opened fire on a car, killing two civilians and wounding a child.

Kyiv dismissed the claims as a "deliberate provocation".