Ukrainian forces said they thwarted a Russian missile attack on the capital Kyiv where air raid sirens sounded before dawn on Sunday.

"This is the third ballistic missile attack on the capital in August with a clear interval of six days between each attack," the Kyiv City Military Administration posted on Telegram after the early morning barrage.

Simultaneous to the missile attack, drones were spotted heading to Kyiv.

"All enemy drones were destroyed far outside the city," it added.

No damage or casualties were reported from the attack, which the administration said had "most likely used North Korean ballistic missiles of the KN-23 type".

The United States and Seoul have accused North Korea of providing ammunition and missiles to Russia for its war in Ukraine.

Kyiv has repeatedly called for its allies in the West to provide more air-defence systems.

Last weekend, a 35-year-old man and his four-year-old son were killed in an overnight Russian missile attack near Kyiv. Three other people were seriously injured.

Concern has deepened after Moscow vowed a "tough response" to the recent Ukrainian advance into Russian territory.

Two and a half years after Russia's invasion of Ukraine, Kyiv's troops last week launched a major counter-offensive into the Kursk region, sending more than 120,000 people fleeing.

Ukraine claims to have seized more than 1,100 square kilometres of Russian territory in the biggest attack by a foreign army on Russian soil since World War II.

On Saturday, Ukrainian President Volodymyr Zelensky said that his army was reinforcing its positions in the Russian region of Kursk with the operation "proceeding exactly as we expected".

On the other side of the front line, Russian air defences destroyed five Ukrainian drones in the Belgorod, Kursk and Rostov regions on Saturday night, the Russian Defence Ministry said.