Ukraine border: As Russia masses its troops President Zelensky heads to the trenches

“If I visit a military base, the guys at the very front will hear about it and think I forgot about them,” Zelensky told CNN in exclusive comments over two days. “They need to know they have political support.”

Zelensky, strapped into a camouflage flak jacket and helmet, has to sprint across the open ground with his presidential security to reach the trench cover.

New boiling point in long standoff

But amid growing tensions with the United States and its Western allies, Russian forces have again been spotted on the move across the border sparking concerns the war may be reignited.

Cell phone video has emerged of Russian armored columns driving towards the Ukrainian frontier. Tanks and artillery guns have been seen being transported by rail. There’s also been a build-up reported in Crimea.

In Moscow, the Kremlin says the troop movements are inside Russia, part of a planned military exercise and pose no threat.

But at the front lines, the Ukrainian President told CNN a Russian invasion is a very real possibility his country is bracing for.

“Of course. We know it, from 2014 we know it can be each day,” he said.

“They are ready, but we are also ready because we are on our land and our territory,” he told CNN.

Lt. Gen. Ruslan Khomchak, commander-in-chief of the Ukrainian armed forces, told CNN an estimated 50,000 Russian troops have now gathered across the Russian border and in Crimea. In addition, there are at least 35,000 Russian-backed separatists in rebel-held areas of Ukraine, he said.

Even before this current worrying build up in the number of troops at Moscow’s command on Ukraine’s doorstep, Zelensky called for the US to sell it weapons, such as Javelin anti-tank missiles. Those weapons have now been delivered, most notoriously in a phone conversation with then-President Donald Trump.

Lurching to the future

From the air, above the muddy trenches, the seemingly endless flatness of eastern Ukraine is punctuated by battered towns and the rusting industrial hulks of the Soviet-era factories that made this war-ravaged region Ukraine’s economic backbone.

Military helicopters, deafening old MI-8s first developed during the Soviet era, painted in unnaturally vivid combat camouflage, fly fast and low over the countryside to avoid ground fire. Every few minutes they lurch upwards to leapfrog trees or electricity lines, then quickly plunge back down again within feet of the soil.

On board the aging presidential chopper, which retains a degree of well-worn comfort, Zelensky shouts above the engine noise of how the US is a “good friend” of Ukraine, but that President Biden “must do more,” to deter Russia and help bring this conflict to an end.

More weapons, more money to fight, and, crucially, more support to join NATO, the Western military alliance where an attack on one member commits all to respond, he explained.

“If they [the US] see Ukraine in NATO, they have to say it directly, and do it. Not words,” Zelensky told CNN.

But the chances of that are slim, amid concerns that moving Ukraine closer to NATO membership would provoke Moscow, possibly fueling a broader conflict.

“Maybe you are right,” Zelensky responds.

“But what now is going on? What we do here? What do our people do here? They fight.”

At the front line, Zelensky led a minute of silence for the fallen.

With or without NATO, this is his country’s reality. Ukraine is at war.