Ukraine on Saturday blasted the "global indecision" of its allies after Germany refused to supply its vaunted Leopard tanks to bolster Kyiv's fighting capacity in the nearly year-long war with Russia.

On Friday, some 50 nations agreed to provide Kyiv with billions of dollars' worth of military hardware, including armoured vehicles and munitions needed to push back Russian forces.

But German Defence Minister Boris Pistorius said that despite heightened expectations, "We still cannot say when a decision will be taken, and what the decision will be, when it comes to the Leopard tank."

"Today's indecision is killing more of our people," Ukrainian presidential adviser Mykhailo Podolyak tweeted.

"Every day of delay is the death of Ukrainians. Think faster," he said.

Several allies echoed Ukrainian President Volodymyr Zelensky in saying the tanks were essential to Ukraine's fight with its much larger neighbour.

In a joint statement the foreign ministers of the three Baltic states urged Germany "to provide Leopard tanks to Ukraine now.

"This is needed to stop Russian aggression, help Ukraine and restore peace in Europe quickly," said a message tweeted by Latvian Foreign Minister Edgars Rinkevics and endorsed by his Estonian and Lithuanian counterparts.

"Germany as the leading European power has special responsibility in this regard."

In Berlin, hundreds of people demonstrated outside the Federal Chancellery building calling for Germany to send tanks to Ukraine.

Berlin has been hesitant to send the Leopards or allow other nations to transfer them to Kyiv.

Reports earlier in the week indicated Germany would agree to do so only if the US provided its tanks as well. Washington has said providing its Abrams tanks to Ukraine is not feasible, citing difficulties in training and maintenance.

But expectations had grown ahead of Friday's Ukraine Contact Group meeting of around 50 US-led countries that Germany would at least agree to let other countries operating Leopards transfer them to Kyiv's army.

In its daily report Saturday, Moscow's forces said they had carried out "offensive operations" in the region and claimed to have "taken more advantageous lines and positions".

Russia also said it had held a training exercise on repelling air attacks in the Moscow region, using an S-300 anti-aircraft missile system.

Ukraine's defence ministry reported 26 air strikes and 15 attacks from multiple-launch rocket systems Saturday. (AFP)