Representatives of around 50 countries gathered at a US airbase in Germany to discuss coordinating military support.

Germany's new defense minister denied blocking the use of its Leopard tanks, which Kyiv has been pushing for, saying such a decision had to be carefully considered.

Ukraine says the tanks are needed to break the deadlock in the war.

Russia has warned that providing tanks would mark an extremely dangerous escalation.

With more, here's our Europe correspondent, Jessica Parker.

This is what Kyiv wants but can't yet have.

German-made Leopard tanks to help defend and reclaim its territory from Russia.

Britain's gone first in sending western main battle tanks, but it's a fraction of what's being asked for.

Hundreds of "thank you" are not hundreds of tanks.

All of us can use thousands of words in discussions, but I cannot put words instead of guns that are needed against Russian artillery.

Defense chiefs have pledged fresh support, but Berlin is still resisting pressure to release its Leopard 2s.

It gets to decide where German-made tanks can go, even those bought by other countries.

Minister, why is Berlin so hesitant on this issue?

We're not really hesitating; we are just very carefully in balancing all the proof and contrast.

We are not talking just about delivering anything to anybody; this is a new kind of measure.

These crowds in Berlin want Germany to do more, but the government has its eye on broader public opinion.

The country's World War II history still casts a long shadow while there are fears of escalation.

But they've not made a decision on the provision of Leopard tanks.

What we're really focused on is making sure that Ukraine has the capability that it needs to be successful right now.

The NATO military alliance is pressing a sense of urgency.

There is a need for support to Ukraine to enable them not only to survive, but actually to retake territory to win this war.

But there's a lot of talk, of course, about a Russian spring offensive, but do you think Ukraine can take back territory this year?

Absolutely, and that's the reason why NATO allies are⏤and partners are providing significantly more support to Ukraine

A soviet-era tank in a war of today.

Frontline Ukrainian units are hungry for more modern weapons to help unfreeze this conflict.

Jessica Parker, BBC News, in Ramstein.

Well, to what extent have Western countries committed to backing Ukraine in the war?

Our diplomatic correspondent James Landale is here to explain. James.

Tina. Throughout the war, Western powers have given Ukraine different weapons at different times depending on what was needed.

At the start, portable anti-tank weapons like these NLAWs were crucial in helping Ukraine resist the Russian invasion.

Then, precision-guided rockets like these HIMARS were given to Ukraine to hold back Russian advances in the south.

And then, it was air defenses including some like these that Ukraine needed to protect itself against drones and missiles.

And now, it's hundreds of powerful battle tanks that they say they need to break the deadlock on the battlefield.

The reason Ukraine is asking for, perhaps, 300 main battle tanks is that Ukraine understands that that number of high-quality tanks really would make a major difference to the battle to take back Ukraine,

whether you're defending it or attacking to take it back.

Britain has promised Ukraine some Challenger 2s, the British Army's main battle tank.

It's sending 14.

Not enough to shift the balance, but enough, it's hoped, to get the ball rolling.

But there is, as yet, no agreement on sending German-made Leopard 2 tanks.

They're easy to maintain, and there are lots of them, almost 2,000 in use across Europe.

But there are fears in Germany that sending them could escalate the conflict.

The great majority of the tanks are actually outside Germany, but you do need German spare parts and logistical support.

So, I hope that after this public discussion, we will come together and do what's necessary.

The West has already given Ukraine a huge amount of military support⏤you can see from this chart in monetary terms.

The United States has given most, and despite the row over tanks, Germany, here, has, nonetheless, given a lot of weapons and ammunition.

Now, this debate about tanks matters because the decisions being taken could shape the next phase of the war and determine which side has the initiative going into the spring.

- Tina. - James, thank you.

James Landale, our diplomatic correspondent.

So, what's Russia thinking about all this?

Let's go live now to our Russia editor Steve Rosenberg, who is in Moscow.

Steve, what does Russia make of what's happened at this meeting of Ukraine's allies?

You know, when it comes to Western meetings, Western summits, there are three words guaranteed to put a smile on Vladimir Putin's face.

No decision taken.

And the fact that no decision was taken to send German battle tanks to Ukraine or American tanks,

that will have gone down very well in the Kremlin,

because the slightest hint of division, disunity, disagreement in the Western camp, the Kremlin latches on to that, it laps it up.

Now, earlier, the official message from the Kremlin was that,

in any case, Western tanks wouldn't really change the situation on the ground; it wouldn't stop Russia from achieving its goals in Ukraine,

which is defiant talk, but the problem for Russia is:

There is no sign of it achieving its goals in Ukraine; there is no sign of an imminent military victory for Russia.

The so-called "special military operation", which was supposed to last just a few days⏤a few weeks, maximum,

has dragged on now for almost a year of war,

with devastating consequences, of course, for Ukraine, but also for Russia's future.