Vladimir Putin revels in his victories on Russia's Defender of the Fatherland Day: President hails his military 'heroes' as his troops capture a city, US blocks Ukraine aid and Alexei Navalny lies dead

President Vladimir Putin on Friday hailed Russia's 'heroes' fighting in Ukraine on the eve of the second anniversary of the Kremlin's offensive, with Moscow bolstered by gains against ammunition-starved Ukrainian troops.

Putin's message came on Russia's 'Defender of the Fatherland Day' patriotic holiday, which has always been an occasion for military pomp and Kremlin-sponsored patriotism.

This year the holiday comes with Putin inspired by the capture of the Ukrainian city of Avdiivka and reveling in the US Congress blocking vital military aid to Kyiv.

'You are our true national heroes,' Putin said in a video message addressed to troops and veterans.

'We know that it is hard for you, and we will do everything possible for you to fulfil the tasks ahead of you,' Putin said, adding that Moscow's weapons production has 'multiplied.'

Vladimir Putin has called his troops 'heroes' after two years fighting his war against Ukraine

The city of Avdiivka fell to Moscow last week after months of bloody battles

Putin's message came on Russia's 'Defender of the Fatherland Day' patriotic holiday

Putin has spent recent days flying in bomber planes, handing out medals to troops and touting a 'turning point' in Ukraine.

He has mocked Ukraine's 'chaotic flight' from Avdiivka, which fell to Moscow last week after months of bloody battles.

Putin has also been bolstered at home, ahead of an election certain to extend his long rule: a massive crackdown has all but crushed dissent and the Russian leader's main opponent - Alexei Navalny - is dead.

Ukraine, meanwhile, has been weakened by the blocking of US aid, its failed counter-offensive and worsening ammunition shortages.

President Volodymyr Zelensky has acknowledged an 'extremely difficult' situation on the front.

Two years fighting a bigger and richer army has taken its toll on Ukraine's stretched forces.

'It's extremely hard,' Ukrainian infantryman Oleksiy told AFP in eastern Ukraine, caked in mud after returning from the trenches.

Vladimir Putin takes part in a wreath laying ceremony at the Tomb of the Unknown Soldier

Now Opposition leader Alexei Navalny is dead, nothing stands in the way of Putin's reelection 

'We don't have weapons like they have. You know, they have factories for production, and us? We beg for weapons. That's the way it is,' the 32-year-old said.

In Moscow, Putin laid flowers at the Tomb of the Unknown Soldier outside the Kremlin walls in a ceremony attended by veterans and Russia's Defence Minister Sergei Shoigu.

The head of Russia's Orthodox Church, a key Putin ally and supporter of the offensive, yet again sanctified it.

In a letter to Putin, Patriarch Kirill said: 'We glorify today the feat of soldiers who are heroically fighting on the borders of Russia, defending its sovereignty and independence.'

Russia has banned all criticism of its campaign, punishing thousands for denouncing the offensive, with repression comparable to late Soviet levels.

It took Putin's army several months to capture the city, causing a huge amount of bloodshed

As Ukrainian forces were forced to evacuate, military items were left behind on the ground

The United States is on Friday to announce new sanctions on Moscow over the death last week of Putin's opponent Navalny in an Arctic prison. His body has not yet been returned to his family.

The UN Security Council will also convene Friday, marking two years of the conflict that has cost tens of thousands of lives.

In Ukraine, foreign dignitaries began to arrive to mark the anniversary of Moscow's assault, which has killed thousands of civilians, on top of a huge number of military deaths.

Denmark's Prime Minister Mette Frederiksen arrived in the western city of Lviv on Friday, Zelensky said.

US senator Chuck Schumer also arrived in the city, close to the Polish border.

Denmark's Prime Minister Mette Frederiksen arrived in the western city of Lviv on Friday

A statue of a soldier amongst the ruins of Avdiivka which has now been taken by Russia

The Democrat said on social media that he wanted to 'show the Ukrainian people that America stands with them' and to 'learn about the arms Ukraine vitally needs.'

Despite recent setbacks, Zelensky has remained defiant.

Kyiv has taken confidence from continued successes on the Black Sea, where it says it has destroyed a third - 25 vessels - of Russia's Black Sea fleet.

But its land campaign has stalled, and it is there that Moscow is seeking to press its advantage and drive further into Ukraine following the capture of Avdiivka.

Kyiv warned Friday that Russia is intensifying attacks around the new 'hot spot' of Maryinka, a town to the west of the Moscow-controlled stronghold of Donetsk city.

Ukrainian troops, however, remained determined.

Raising a glass to his army - Vladimir Putin calls his soldiers 'heroes' as they take Avdiivka

Ukraine's land campaign has stalled - Moscow is seeking to press its advantage

Ukrainian soldier Oleksiy who was holding the fallback lines outside Avdiivka, said that while the fall of the industrial hub affected morale, troops were ready to fight on.

'Absolutely, of course we were upset. But nevertheless, nobody's discouraged,' he said, with an AK-47 assault rifle tattooed on his neck.

'If we retreat, they will move all along the front line.'