"We need missile and air defence. Reinforced, powerful, modern and capable of counteracting the types of missiles that the enemy uses against us," Ukrainian army spokeswoman Nataliya Gumenyuk said in an interview on Wednesday.

Ukraine has received sophisticated air defence system from its Western allies, including US Patriots.

But Gumenyuk said that Russia is "improving its tactics every time, it doesn't stop."

Earlier this month Russia exited a landmark deal that allowed the shipment of around 33 million tonnes of grain to leave Ukrainian ports.

Russian forces "want dominance in the Black Sea. They want a grain monopoly for themselves", Gumenyuk said.

"They want to close Ukraine as a country that can feed the world," she added.

Since the deal expired, "virtually all ports are blocked. No ship can leave", Gumenyuk said.

Attacks on the southwestern Odesa region on the Black Sea coast have increased since the expiry of the deal.

Gumenyuk said Ukraine needed air defence quickly to protect grain facilities from these strikes.

"We will not need (air defences) in two or three months. We may not have ports anymore," she warned.