Germany will deliver to Ukraine an air defence system capable of shielding a "large city" from Russian air raids, Chancellor Olaf Scholz said Wednesday, rejecting accusations his government had been slow to arm Kyiv.

Scholz told parliament Berlin would also be sending more weapons to Ukraine.

"The government has decided that we will send the Iris-T system -- the most modern system that Germany currently possesses," he said.

It would "enable Ukraine to protect an entire major city from Russian airstrikes", he said.

Germany will also deliver a tracking radar system capable of detecting enemy rocket artillery, he added.

Foreign Minister Annalena Baerbock admitted however that it would take months for the air defence system to reach Ukraine.

The Iris T due to be transferred was originally bound for "another country" but manufacturer Diehl agreed to divert it to Ukraine instead, said Baerbock.

The air defence system has previously been delivered to Egypt.

The German army has Iris T-missiles in its inventory but not the complete surface-to-air system. It fires the missiles from Tornado or Eurofighter jets.

Referring to US President Joe Biden's announcement that the United States would send more advanced rocket systems to Ukraine, Scholz said Berlin would "contribute what is within our technical capabilities".

Under political pressure over the last weeks, Scholz's government has agreed to send heavy weapons including self-propelled howitzers and Leopard tanks to Ukraine.

On Tuesday, Scholz said in Brussels he had agreed a deal with Greece for Athens to send Soviet-era military vehicles to Ukraine in exchange for more modern armour from Berlin.

Germany also wants to deliver 14 Leopard battle tanks and one Leopard armoured vehicle to Prague in exchange for the Czechs sending T-72 tanks to Ukraine.

But no delivery date has been fixed and Scholz told parliament talks were continuing.

Germany says it is also negotiating a similar deal with Poland.

The goal is to supply Ukraine with vitally needed weapons from old Soviet-era stocks that it can quickly put into battle as it tries to halt Russia's invasion.