Don’t Trust – Do Verify: That’s the unofficial mantra from Western officials in response to Russia’s declarations that some of their units that have been encircling Ukraine are now returning to base.

Russia appears keen to prove those declarations to the world through well-produced videos distributed by the Ministry of Defense on Tuesday and Wednesday.

In several of those videos, units from the Southern and Western Military Districts were said to be going back to base from Crimea after completing their exercises there. Traffic heading east across the bridge over the Kerch Strait included tanks, infantry fighting vehicles and fuel trucks, which supported the units.

Filmed from multiple angles, the videos were designed to reinforce what the Kremlin has insisted all along: that an invasion of Ukraine is not and never has been on its agenda.

“Southern Military District troops, which have completed their tasks as part of planned tactical exercises at combined arms ranges on the Crimean peninsula, have begun to return to their permanent deployment points,” the ministry said Tuesday.

But two of the units leaving, according to Russian newpaper Izvestia, were elements of the 3rd and 150th Motor Rifle Divisions. They are based close to Ukraine at Rostov-on-Don and Belgorod respectively, a short drive from the border. When those units get home, they will be closer to Ukraine than they were in Crimea.

Other Russian footage from Tuesday – including drone shots – showed the elaborate departure of T72 tanks from an unidentified rural area.

CNN geolocated the location to a training ground near Otreshkovo, a Russian village some 120 kilometers (around 75 miles) from the border. But the direction the departing tank convoy was taking is far from conclusive.

The video shows tanks heading in two different directions, both to a railway station and to the training ground.

The next day, the defense ministry posted more video of the same unit being loaded onto a train – and then later published another video of the train rumbling eastwards at night. Its destination is unknown.

Russian diplomats have seized on the Defense Ministry’s declared pull-back to accuse the West of hysteria in amping up the threat of an invasion.

Russia’s Ambassador to the European Union Vladimir Chizhov told German newspaper Die Welt on Wednesday that there will be no attack on “Wednesday, next week, neither in the coming weeks, nor months.”

For the United States and NATO, the jury is still out. US President Joe Biden said Tuesday the US assessed there are some 150,000 Russian forces surrounding Ukraine.

NATO’s Secretary-General, Jens Stoltenberg concurred, saying, “just that we see movement of forces, so battle tanks, doesn’t confirm a real withdrawal. It has been a bit up and down, back and forth all the way.

But the trend over the last weeks and months has been a steady increase in the Russian capabilities close to Ukraine’s borders.”

CNN – along with a number of independent experts – continues to monitor and geolocate social media content emerging from Russia and Belarus that show its military on the move.

The evidence to hand is that plenty of Russian armor remains close to the Ukrainian border – and some of it is still moving closer.

On Wednesday, T90 tanks were filmed moving through slush in Tomarovka, a village in the Belgorod region of Russia just miles from the Ukrainian frontier, according to multiple videos reviewed.

In the nearby, village of Veselaya Lopan, satellite imagery shows a new temporary military camp.

And in the past week, more helicopters – for both combat and transport – have arrived both in Crimea and in areas close to Ukraine’s eastern border, according to satellite imagery reviewed by CNN.

Those helicopters would provide important air support to any ground offensive.

New satellite imagery also shows a curious development in southern Belarus, around six kilometers (approximately four miles) from the Ukrainian border and also close to the Chernobyl Exclusion Zone. A long pontoon bridge has been built in the last few days across the River Pripyat, not far from where Belarus and Russian forces are carrying out extensive joint exercises.

While there is little military activity in the immediate area, the bridge would dramatically cut the time needed to reach the Ukrainian border and avoid population centers. An additional satellite image from Planet Labs also shows that after January 8, a new road was constructed that leads to the bridge.

Western intelligence and military officials are closely tracking the construction as part of the support infrastructure Russia is putting in place in advance of a potential invasion, three sources familiar with the matter told CNN.

Still, past exercises in the area have included the construction of pontoons, highlighting a well-known dilemma in intelligence capture: how to reconcile growing and changing capabilities with unknown intent.

Another as yet unexplained development: Maxar had previously observed the establishment of a large detachment of Russian forces – including tanks – near the town of in south-eastern Belarus, some 30 miles from the border.

Those forces appear to have dispersed, Maxar says, noting that a “military convoy was seen moving west on today’s imagery.”

Analysts say it will take at least several days to establish whether there is a true drawdown of Russian forces from temporary positions around Ukraine, or whether – as many western officials believe – it’s more maneuvering.

The Conflict Intelligence Team, which has long experience tracking Russian military movements, told CNN: “We are currently unable to either confirm or deny any actual withdrawal happening. We’ve seen vehicles of the 58th army of the Southern Military District being loaded on trains in Crimea (where they had previously deployed unannounced), but we would need some additional time and evidence to say if they are actually withdrawing to their permanent bases.”

Konrad Muzyka, an analyst at Rochan Consulting, an aerospace and defense consultancy said in a tweet, “Previously announced withdrawals meant more Russian troop deployments near Ukraine. New trains with equipment keep on arriving. The withdrawal would be a welcome development, but recent history tells us these announcements are not genuine. Need a few days to verify.”

In January and early February, dozens of social media videos showed Russian forces heading towards Ukraine’s borders nearly every day. So far, there’s been no similar surge of content showing those forces moving in the opposite direction.