Ukraine is increasingly using robotic ground machines to offset one of its most pressing wartime challenges: a shortage of manpower.

They ferry supplies, clear mines and evacuate the wounded or dead from areas too dangerous for soldiers.

Robotic vehicles are not new in warfare.

The German army used a wire-guided miniature tank in the Second World War II.

In recent decades, the U.S., Britain, Israel, China and others developed modern versions for combat engineering and other battlefield roles.

But analysts say Ukraine’s extensive deployment of these vehicles is noteworthy and could lead to advances.

Some commanders believe the technology is only at the dawn of its development.

They think the machines will soon become essential in a war where combat has drastically changed under Russia’s invasion.

Ukrainian soldiers have welcomed the introduction of what they simply call “the robot on wheels”.

The machines are nimble, mobile and not particularly fast, but always ready to work.

They say the main advantage of a robotic ground machine is obvious: it is not human.

Each time it takes on a mission, it spares a soldier from stepping into deadly risk.

On a battlefield thick with drones and artillery, that means one less life exposed while an urgent task is still carried out.

The robotic ground machines resemble small armored vehicles, often mounted on tracks or wheels like a miniature tank.

Painted in military colors, they crawl slowly over rubble or along dirt roads, built to navigate terrain too dangerous for soldiers.

The robotic vehicles are mostly made by Ukrainian companies.

They range in cost from about 1,000 to as much as 64,000 U.S. dollars, depending on their size and capabilities.

Many brigades across the front are now introducing such machines, though some are further along than others.

A 10-man team of the "Lubart" (or Lyubart) Brigade has begun integrating the machines into the workflow, mostly using them for logistic purposes.

One serviceman, who goes by the call sign "Akim", says that the robotic machines help save the lives of fighters.

Before sending a robotic vehicle forward, he flies a reconnaissance drone along the planned route to check for obstacles or mines.

He operates it from a cramped basement near Kostiantynivka, less than 10 kilometers (6.2 miles) from the front.

The muffled thuds of aerial bombs and the sharp cracks of artillery and drones can be heard even underground.

Kostiantynivka, once home to 67-thousand people, now lies largely deserted.

The city sits on a shrinking patch of Ukrainian-held territory just west of Bakhmut and is nearly encircled on three sides by Russian forces.

Buildings are scarred by strikes, smoke still rises from recent attacks, and the roads leading toward nearby Pokrovsk are littered with burned-out cars.

Akim works in tandem with another soldier operating the robotic vehicle with a joystick.

The vehicle has no camera; instead, Akim’s drone feed provides its “eyes”.

On one mission, the team loaded it with 200 kilograms (441 pounds) of supplies - ammunition, fuel, water and food.

The supplies were meant for drone operators positioned several kilometers (miles) ahead, much closer to the front.

The machine trundled forward at about six kilometers (3.7 miles) per hour.

It delivered its cargo into well-hidden position in the forest line, and returned to base.

But despite their promise, there are some obstacles that prevent the robots from becoming a significant game-changer.

The machines move slower than a car and usually across open ground, which makes them an easy target.

They also require constant modification.

Ukrainian crews try improvised protection, welding grill-like cages onto the machines or metallic rollers attached in front to detect mines.

They continue searching for ways to protect the robots while offering real-time feedback on how the technology performs in modern warfare.

AP video by Vasilisa Stepanenko