A month before a highly symbolic May 9 parade on Red Square that celebrates victory in World War II, Russian President Vladimir Putin's troops face considerable challenges in Ukraine.

Here are some of Moscow's military and social objectives:

Take Donbas 

After encountering fierce resistance around Kyiv, Moscow in late March said it would focus on the eastern region of Donbas, where Russian is traditionally spoken more than Ukrainian.

The coal mining region is vital to Ukraine's economy but has suffered since 2014, when the Ukrainian army began fighting Moscow-backed separatists.

Putin's aim appears to be to seize the whole region, only part of which is controlled by Moscow-backed separatists.

While there has not been a "mass redeployment" of troops eastwards, "we've seen the early stages of some of the … airborne forces starting to make their way to join the forces in or around the Donbas", a senior Western official said.

After Russia's initial operation suffered major logistical difficulties, its General Staff will try to plan more carefully to avoid a drawn-out conflict. 

Hold triumphant May 9  

Given the significance of May 9 when Putin reviews troops beside the Kremlin and gives a speech on Russia's capabilities, the armed forces face pressure to achieve results.

Putin will want to draw parallels between the Soviet victory over Nazi Germany and his avowed aim to "de-Nazify" Ukraine.

"We believe the 9th of May is a significant date for the Kremlin," the Western official said, warning that tailoring military action to fulfil political goals, "can end up with a military disaster". 

However, Vasily Kashin, a geopolitics expert at Moscow's Higher School of Economics, said the date "does not play any role at all".

"This is a hard war, the largest in Europe since 1945", he told AFP. "No one is going to time anything to fit with a public holiday."

While taking the whole of Donbas by May 9 appears an uphill task, Russia may hope to gain full control over the encircled port city of Mariupol and declare this as a victory.

Continuing talks 

While its military action continues, Moscow has also participated in peace talks with Kyiv.

The Kremlin has blown hot and cold and on Thursday accused Kyiv of diverging from proposals put forward at a previous meeting, after saying some progress had been achieved.

Experts say Russia wants to achieve a military breakthrough before engaging in serious negotiations.

Kashin said the talks will be "determined by the dynamics of the military action".

The biggest sticking point is the "status of Crimea and Donbas", with Russia insisting the former must be recognised as part of its territory and the latter as independent, Kashin said.

Russia will seek to push through those goals, Kashin added.

"The question is how long it will take and what the losses will be on each side."

 Keep the economy afloat 

Putin cannot just focus on military manoeuvres but must also keep watch on economic indicators as Western sanctions start to bite with rising inflation.

Sergei Khestanov, a macroeconomics adviser with dealer Open Broker, said the impact will start to be felt in "in three or four months" as "logistical difficulties build up". 

Russian Prime Minister Mikhail Mishustin said Thursday that the economy would need "at least half a year to rebuild".

The state is making heavyhanded interventions, raising fears of a return to a Soviet-style centrally planned economy. 

On Tuesday, Putin called for the manufacture of more secondhand agricultural equipment and for setting  "clear" goals to compensate for the suspension of imports.

"Fortunately among the authorities there are quite a few people who understand that the introduction of state planning would greatly hasten collapse," said Khestanov.

Muzzle the opposition 

Moscow has stepped up repressive measures, detaining thousands of protesters and blocking independent media and social media.

As a result, 83 percent of Russians say they back Putin's actions, according to a March vote by the independent pollster Levada Centre but this has to be put in the context of a fear of speaking out.

Russia is also stepping up anti-Western rhetoric.

Foreign Ministry spokeswoman Maria Zakharova on Wednesday accused Western media of "complicity" in the killings in the town of Bucha, where Putin denies any involvement and accuses Kyiv of a "crude and cynical provocation".

Former president and prime minister Dmitry Medvedev gave a speech this week saying Russia aims to "build an open Eurasia, from Lisbon to Vladivostok".