On Tuesday, a Russian armoured column advanced on Ukraine’s capital, Kyiv, after the fatal bombardment of civilian areas in the country’s second largest city suggested that frustrated Russian commanders could turn to more lethal means to achieve their invading aims.

Nearly a week after unleashing its assault on its neighbor, Moscow’s soldiers have failed to conquer a single major Ukrainian city due to stiff opposition.

Despite the fact that Russian President Vladimir Putin is facing worldwide censure and international sanctions for his acts, it still has more forces to throw into the fray.

Oil company Shell became the latest Western firm to announce it was pulling out of Russia. The sanctions and global financial isolation have already had a devastating impact on Russia’s economy, with the rouble in freefall and queues outside banks as Russians rush to salvage their savings.

Kyiv was still in the hands of President Volodymyr Zelenskiy’s government, with soldiers and civilians ready to fight the invaders street by street.

But pictures released by U.S. satellite company Maxar showed Russian tanks and fuel trucks stretching for 40 miles (60 km) along a highway and bearing down on Kyiv from the north.

“For the enemy, Kyiv is the key target,” Zelenskiy, who has remained in the capital rallying Ukrainians, said in a message overnight.

“We did not let them break the defence of the capital, and they send saboteurs to us…We will neutralise them all.”

Ukrainian presidential adviser Oleksiy Arestovych said Russian forces were trying to lay siege to Kyiv and Kharkiv, Ukraine’s second-largest city near the Russian border in eastern Ukraine.

Russian troops fired artillery at Kyiv, Kharkiv and the southern port city of Mariupol overnight while the Ukrainian side shot down Russian military planes around the capital, Arestovych said in a briefing.

Ukrainian authorities also reported 70 soldiers killed in a rocket attack in a town between Kyiv and Kharkiv.