Fighting is raging and Kyiv is relentlessly pressing its allies for more military hardware. 

But has Ukraine's long-promised counter offensive against the Russian invasion actually begun?

Analysts say Ukraine has stepped up its activity along the front line, seeking notably to pin Russia down and inflict maximum casualties around the flashpoint town of Bakhmut.

Meanwhile, President Volodymyr Zelensky has been on a whistlestop tour of European allies, winning pledges from Britain, France and Germany of increased military support while insisting Kyiv needs more.

Western capitals are eager to see the offensive start, in the hope Ukraine can make gains, force Russia to the negotiating table on Kyiv's terms and open a path to ending the conflict.

Ukraine is seeking to take back control of territory occupied by Russian forces in the wake of the February 2022 invasion and also areas, including Crimea and parts of the Donbas, seized by Russia in 2014.

The battle for Bakhmut in eastern Ukraine has turned into the longest standoff since the Russian invasion.

Ukraine is now saying it is advancing in the area, retaking Russian positions in Bakhmut's suburbs.

"I lean towards the interpretation that Ukraine is fixing Russian forces in Bakhmut to keep them committed to a particular front while Ukrainian forces probe different areas," said Ivan Kłyszcz, a research fellow at the International Centre for Defence and Security in Estonia.

"My preliminary conclusion is that these probing and shaping operations will be ongoing but remain at the tactical level, that is, until the leadership decides the best moment to launch a larger operation," he told AFP.

- 'Probing Russian defences' -

Moscow's forces switched several weeks ago into a defensive posture, employing a large number of soldiers, sometimes three lines deep, to hold positions.

Their set-up includes anti-tank ditches, barriers, pre-fabricated lines of defence like the small anti-tank concrete pyramids known as dragon's teeth, and trenches for the men. 

The Ukrainian counter-offensive consequently risks being deadly and costly in terms of equipment for Kyiv. 

But it appears Ukraine has started a period of tests to measure the effectiveness of this defence.

"Ukraine has conducted local counter-offensives in and around Bakhmut to roll back Russia’s flanks and gauge defences in the region. 

"Elsewhere, Ukrainian forces are likewise probing Russian defences and reaction behaviours," said Lucas Webber, co-founder and editor of the Militant Wire news site on global military activity.

He said it was "difficult" to say whether the full planned counter-offensive has begun.

"However, these actions suggest Ukraine is preparing for something much larger. 

"These could be shaping operations to put Ukraine in a better position when the real action starts."

He said the full counter-offensive was likely to involve multiple fronts, including operations to take back the parts of the Zaporizhzhia region it does not currently control. 

That includes the Zaporizhzhia its nuclear power plant which is still occupied by Russian forces, and the south of the region.

Taking Bakhmut in itself would be a blow to Russia. 

The city's symbolic importance after such a long battle now outstrips its strategic value, especially given the resources used by the Russian army and the Wagner mercenary group under Yevgeny Prigozhin.

"A successful Ukrainian campaign in the region would frustrate Russia and set Moscow's war efforts back considerably," said Webber.

- 'Push the other into a mistake' -

Further intrigue comes from the increasingly volatile behaviour of Prigozhin, who is becoming ever more scathing in his criticism of the Russian defence ministry and on Friday accused the Russian army of "fleeing" rather than regrouping around Bakhmut.

A report in the Washington Post on Sunday said Prigozhin had maintained contact with Ukrainian intelligence throughout the war and had even in January offered to give Kyiv information on Russian troop positions if Ukraine's commanders withdrew their soldiers from the area around Bakhmut.

Some commentators are now arguing he had crossed a line and risks antagonising Russian President Vladimir Putin but Prigozhin has dismissed the allegations as "laughable".

Pierre Razoux, academic director of the France-based Mediterranean Foundation of Strategic Studies (FMES), said the current situation was characteristic of a phase where both sides were using feints and games to deceive the other ahead of a major operation.

"The preparatory phases of clandestine actions and deceptions and manipulations seems to have been well launched on both sides," he said.

"Each side is probably trying to push the other side into a mistake by convincing them to attack where they seem weakest."

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