President says Ukraine has a quarter of air defences required to hold front line as Russia advances along northeastern border.
Russian forces, which had made only moderate advances in recent months, launched a surprise assault in the Kharkiv region on May 10 that resulted in their biggest territorial gains in a year and a half.
Zelenskyy conceded on Friday, in an interview with the AFP news agency, that Ukraine only has a quarter of the air defences it needs to hold the front line while the war grinds on.
He said Russian forces managed to advance between five to 10km (3-6 miles) along the northeastern border before being stopped by Ukrainian forces.
On Saturday, Kharkiv’s Governor Oleg Synegubov said “a total of 9,907 people have been evacuated” from the region following a ground attack by Russian troops.
Al Jazeera’s John Holman, reporting from Kharkiv, said that at present Ukraine is “outmanned in terms of soldiers” in parts of the front line even before the latest Russian attacks.
“Ukraine said that there were seven Russian soldiers to one Ukrainian soldier, so that’s going to put fresh pressure on them,” he said.
In an effort to increase troop numbers, Zelenskyy signed two laws, one to enable prisoners to join the army and another that increases fines for draft dodgers fivefold, which go into effect on Saturday.
The president acknowledged that Russian forces were “going deeper into our territory”, adding that in order to achieve at least a level of air “parity” with Russia, Ukraine needs “120 to 130” F-16 fighter jets or other advanced aircraft.
“Today, we have about 25 percent of what we need to defend Ukraine. I’m talking about air defence,” he told AFP.
President Vladimir Putin said on Friday that the offensive in the Kharkiv region is aimed at creating a buffer zone and Russia has no plans to capture the city of Kharkiv.
Speaking to reporters while on a visit to China, Putin said Moscow launched its attacks in response to Ukrainian shelling of Russia’s neighbouring Belgorod region.
“I have said publicly that if it continues, we will be forced to create a security zone, a sanitary zone,” he said. “That’s what we are doing.”
Meanwhile, the commander-in-chief of the Armed Forces of Ukraine, Colonel General Oleksandr Syrskii, said Russia’s new offensive has “expanded the zone of active hostilities” by almost 70km (45 miles) to attempt to force Ukraine to spread its forces and use reserve troops.
In response to the new attacks, Ukraine launched a counterstrike and drone raids on the Russian-occupied Ukrainian territory of Crimea.
A Ukrainian intelligence official confirmed to The Associated Press news agency that the country’s intelligence services struck Russia’s military infrastructure sites in Novorossiysk, on the Black Sea coast, and in the Russian-occupied city of Sevastopol.
The operation, carried out by Ukraine-built drones, targeted Russian Black Sea Fleet vessels, the unnamed official said.
Russia’s Ministry of Defence said 51 Ukrainian drones were downed over Crimea, 44 over the Krasnodar region of Russia and six over the Belgorod region. Russian warplanes and patrol boats also destroyed six sea drones in the Black Sea, it said.
Mikhail Razvozhayev, the governor of Sevastopol, which is the main base for Russia’s Black Sea Fleet, said the drone attack damaged the city’s power plant.