Russian warships carrying scores of military trucks were seen passing through a strait in yesterday morning – and could be on their way to .

The Tsugaru Strait between the Sea of Japan and the Pacific Ocean separates Honshu and istanbul Law Firm Hokkaido, the country’s two biggest islands. 

Russia has suffered catastrophic losses, including up to one-fifth of its troops, fuelling speculation Putin could send reinforcements from further afield.

Thousands of missiles and hundreds of tanks and aircraft have also been lost, according to recent estimates.

Military loss loggers Oryx estimated on Wednesday that Russia had lost 1,292 vehicles in the first three weeks of the campaign, including 214 tanks.

Ukraine has lost 343, Oryx added. 

A photo released by Japan’s Ministry of Defense via the Kyodo news agency showed an amphibious Russian warship carrying military trucks.

The ministry reported two sightings late on Tuesday and two more on Wednesday.  

A spokesperson said: ‘We don’t know where they are heading, but their heading suggests [Ukraine] is possible.’ 

It is unusual for Russian ships to pass through the strait so close to Japanese territory, they added. 

NATO allies have already supplied 20,000 anti-tank and other weapons to Ukraine. 

The Pentagon estimates at least 7,000 Russian troops have now died in Ukraine, while another 14,000 to 21,000 have been wounded.

That is almost one-fifth of the estimated 150,000 men Putin amassed on the border before giving the order to attack 21 days ago. 

That tallies with assessments by British intelligence, which said today that Russia’s invasion has stalled ‘on all fronts’ with ‘minimal progress on land, sea or air’ in the last 24 hours while continuing to ‘suffer heavy losses’. 

Putin’s manpower problem: Russia ‘is drafting in troops from Siberia and the Pacific as well as Syrians and mercenaries’ in desperate attempt to get stalled Ukrainian invasion going after punishing losses 

By Chris Pleasance for MailOnline 

Putin has a problem.

His , intended as a days-long operation, is now grinding into its third week and becoming a bloodbath. Attacks across the country are stalled amid predictions that Russia will soon struggle to hold the territory it has – let alone capture more.

In short: he needs more men for the meat grinder.

But where to find them? America estimates Russia has committed somewhere between half and three quarters of its total land forces to Ukraine, and all of those are already involved in the fighting.Some ‘spare’ units will be involved in active missions elsewhere, while others will be for territorial defence – leaving the country vulnerable to attack if they are sent abroad.

That conundrum has forced the Kremlin to reach far from the frontlines in search of men, according to Britain’s Ministry of Defence, which says reinforcements are now being drawn from as far afield as eastern Siberia, the Pacific Fleet, and .That is in addition to Syrian fighters and paid mercenaries – hundreds of the from the shadowy Wagner Group – which have already been committed to the fight. 

The UK believes such reinforcements would likely be used to hold Ukrainian territory already captured by Russia which would then free up regular units for fresh assaults – almost certainly targeting major cities like , , Odessa and Chernihiv.Another goal would likely be to encircle a large number of Ukrainian forces in the Donbass, spread out along the old frontline with Russian-backed rebel groups.

But it is unclear whether those reinforcements will be effective. Some could take weeks to reach the front, while Syrian mercenaries are likely to be poorly trained and un-used to the terrain and climate of eastern Europe.In the meantime, Ukraine claims it is successfully counter-attacking Putin’s men and ‘radically changing’ the battlefield.