Checkpoints, barricades, and roadblocks radiate from the imposing streets in the city centre to the motorways on the outskirts. Spiky metal tank traps - called hedgehogs - have mushroomed at strategic locations. Troops are more alert, checking every car. Some still smile and say "welcome", but many look distracted, already focusing on the battle to come.
It feels like Ukrainian forces in the capital are poised and ready to fight. This ancient city - with its elegant facades and onion domed churches - is now on a war footing.
Russia's advance has clearly not gone to plan for President Vladimir Putin. With the invasion now in its second week, his troops and tanks are still outside the capital - but maybe not for long. Ukrainian forces we spoke to on Thursday expect the Russians to reach Kyiv in a day or two.
So, deep in a forest on the outskirts of the city, men from Ukraine's territorial defence units are digging trenches.
"Welcome to our party," said the soldier who dropped us off, after a bumpy ride in the back of a military truck full of ammunition boxes.
The scene is somehow reminiscent of World War Two. There's no heavy machinery, just a shovel in every hand. It's a rush job to block the path of Russian forces. We cannot identify the location. One man wields a chain saw, doing battle with a stubborn pine tree.
Mykhaylo blends in with the forest. The 25-year-old computer programmer stands proud, in full camouflage gear. He joined a territorial defence unit earlier this year and got just a few days of training, but he insists he's combat ready.
"I am not afraid," he said firmly. "We are prepared, and we have a lot of powerful guys there. There is a big possibility that the Russians won't even come here. I am very confident in our armed forces. If the Russians make it this far, we will push them out".
Nearby others - both veterans and younger volunteers - were getting a crash course in battlefield first aid. They were being shown how to apply a tourniquet to their own limbs, or to someone else's, while flat on the ground. The aim is to prevent catastrophic blood loss, a leading cause of death in war.