Kyiv, Ukraine(CNN) A drive through central Kyiv leaves no room for doubt. This is a city preparing for a major Russian attack.
Rows of concrete panels arranged in maze-like formations. Anti-tank road blocks. Piles of sandbags. Improvised barriers built of random pieces of metal, wood, old tires or anything that was at hand.
And everywhere you look, there are blue and yellow Ukrainian flags.
The city is uncannily quiet. Many people have fled in recent days. Those who have stayed are hunkered down in bomb shelters, basements and subway stations.
The checkpoints dotted along the city's entry points are manned by ordinary Ukrainians. These are not soldiers. A week ago, many of these men would have been at work, or enjoying time off with their friends and families.
Now, they are ready to defend their country's capital.
Oleksiy Goncharenko was guarding one of the checkpoints in Kyiv on Tuesday, armed with the rifle he picked up last week after answering the call from Ukrainian authorities to prepare to defend the country.
It was bitterly cold, and Goncharenko was working in shifts, with other volunteers. When not at the checkpoint, he says he is at the base, helping wherever he can: "Humanitarian help, helping people to get [to places], organizing transport, sharing information."
Goncharenko is not — and has never been — a military man. He is a member of Verkhovna Rada, the Ukrainian parliament,
"I'm not a professional soldier at all, but I can try and I can do my best and I will do it if Russian forces enter Kyiv," he told CNN.
Most of the men at the checkpoints are smiling. When a car passes through, they greet its passengers, wave and wish them a safe journey, wherever they are going.
A man wearing glasses, a camouflage hat and woolly gloves with six of their 10 fingertips cut off flashes a quick V-sign and waves.
The men here are trying to keep morale high, though they know only too well that the enemy they are facing is much better equipped.
Russia has amassed a 40-mile-long (64-kilometer) military convoy -- made up of armored vehicles, tanks, towed artillery and other logistical vehicles -- that is approaching the outskirts of Kyiv.
Most -- but not all -- of the men in the capital's streets are equipped with rifles. They are stationed alongside the road that connects Kyiv's city center with its suburbs.
Armbands fashioned from a piece of yellow tape indicate they are part of the Territorial Defense Forces, a branch of Ukraine's armed forces that is comprised mostly of volunteers. Tens of thousands have joined up in recent days.
Some look very, very young, wearing tracksuit bottoms and sneakers. In freezing cold weather, the city's defenders -- along with everyone else in Kyiv -- await whatever is yet to come.