But the sluggishness in the actual delivery of heavy weapons to bolster Ukraine against Russia's invasion has raised questions as to whether the Social Democrat's pledges are sincere.

As Scholz arrived in Kyiv for his long-awaited trip on Thursday, he was seeking to restore confidence among Germany's allies over the repeated rows over the urgently awaited arms.

"We want to show not only solidarity, but also assure that the help that we're organising -- financial, humanitarian, but also, when it comes to weapons -- will continue," Scholz told German media on the way to Kyiv.

"And that we will continue it as long as it is necessary for Ukraine's fight" to defend itself against Moscow, he said.

Ukrainian President Volodymyr Zelensky had this week ramped up the pressure on the German chancellor, singling Berlin out as a laggard in weapons supply.

"Every leader of our partner countries, and naturally the chancellor as well, knows exactly what Ukraine needs. It's just that the (weapons) deliveries from Germany are still less than they could be," Zelensky told Wednesday's Die Zeit weekly.

In a hint of what he seemed to think might be holding Scholz back, the Ukrainian president added in a separate interview with public broadcaster ZDF that "there must be no attempt at a balancing act between Ukraine and the relationship with Russia".

Scholz himself has batted off the accusations, as he underlined that Germany "will deliver all the weapons that we have set in motion".

He argued, however, that there was no point in sending complicated modern weapons without first training Ukrainian troops on how to use them.

Training is underway in Germany, he told a press conference this week, stressing that the weapons would follow once soldiers know how to deploy them effectively.

"I think that it would be a good thing for some people to think for a moment before they express an opinion," he added, in a sign of irritation at the repeated queries.

'Middle of road'

But observers said the bad press was not surprising given the stuttering German response compared to other major Western allies such as the United States or Britain, or even when put proportionally next to much smaller eastern European nations like the Baltic states.

Marina Henke, director of the Hertie School's Centre for International Security, said the problem is that "confusion" still reigns in the chancellery over how to handle Russia.

"There is no clear sense of direction," she told AFP, noting the US, Britain and eastern Europe have all identified Vladimir Putin's Russia as the clear enemy and therefore taken the lead in plying Ukraine with arms.

"Here in Germany, there is the idea that Russia is a massive country on our doorstep and in all these actions, we need to think about how we can live with Russia in the long term," she said.

"That's why there is a confusion" that means major weapons pledges are being held up by Germany's complex bureaucracy, she added.

Marcel Dirsus of the Institute for Security Policy at Kiel University also noted that "the German government appears quite content to take a middle-of-the-road approach where they're doing enough to avoid the most severe criticism, but they're not really taking any initiative to go beyond that.

"It's almost a deliberate attempt to do as little as they can get away with."

'Huge fog'

Among the latest weapon promises made by Germany have been the Iris-T air defence system and the Mars II multiple launch rocket system.

But hours after Scholz mentioned the Iris-T, Foreign Minister Annalena Baerbock poured cold water on a swift deployment, warning it would take months before the air defence shield reached Ukraine.

The rocket launchers are due to arrive reportedly in August or September but on condition, Ukrainian soldiers are trained to use them by then.

Gepard anti-aircraft tanks pledged in April have been delayed to July at the earliest due to an ammunition shortfall.

Seven self-propelled howitzers promised in May are pending amid ongoing training of Ukrainian troops.

Poland has accused Germany of failing to provide Leopard battle tanks to make up for the ones that Warsaw had sent ahead to Kyiv.

The Czech Republic is also waiting on a similar swap deal, but talks are still on.

Marie-Agnes Strack-Zimmermann, the defence expert of the liberal FDP, a junior partner in Scholz's coalition, said his visit to Kyiv was an opportunity to clear things up.

"After the resentments from the past weeks, there is now a good chance to speak plainly together," she told news media group Funke.

"Zelensky can describe the situation and say which weapons he wants and needs. Scholz can openly say what can be done and what can't. And then we need to do what we can," she said.