German Chancellor Olaf Scholz is expected to announce his government will approve supplying tanks to Ukraine.
It comes after weeks of hesitation – which saw growing impatience among the country’s allies.
The long-awaited decision follows US officials saying a preliminary agreement has been struck for the United States to send M1 Abrams tanks to help Kyiv push back Russian forces entrenched in the east almost a year since the start of the war.
Mr Scholz had said any move to provide Ukraine with powerful Leopard 2 tanks would need to be closely co-ordinated with Germany’s allies, chiefly the United States.
By getting Washington to commit some of its own tanks, Berlin hopes to spread the risk of any backlash from Russia.
Kremlin spokesman Dmitry Peskov described German and US intentions with the tanks as a “a rather disastrous plan”.
“I am convinced that many specialists understand the absurdity of this idea,” Mr Peskov told reporters on Wednesday.
“Simply because of technological aspects, this is a rather disastrous plan. The main thing is, this is a completely obvious overestimation of the potential (the supply of tanks) would add to the armed forces of Ukraine. It is yet another fallacy, a rather profound one,” the Kremlin official said.
Mr Peskov predicted “these tanks will burn down just like all the other ones. … Except they cost a lot, and this will fall on the shoulders of European taxpayers,” he added.
Ekkehard Brose, head of the German military’s Federal Academy for Security Policy, said tying the United States into the decision was crucial to avoid Europe facing a nuclear-armed Russia alone.
But he also noted the deeper historic significance of the decision.
“German-made tanks will face off against Russian tanks in Ukraine once more,” he said, adding that this was “not an easy thought” for Germany, which takes its responsibility for the horrors of the Second World War seriously.
“And yet it is the right decision,” Mr Brose said, arguing it is up to Western democracies to help Ukraine stop Russia’s military campaign.
Members of Mr Scholz’s three-party coalition government welcomed the news ahead of the official announcement, expected in a speech to parliament early on Wednesday afternoon.
“The Leopard’s freed!” said German politician Katrin Goering-Eckardt, a senior Green party member.
Marie-Agnes Strack-Zimmermann, a member of the Free Democratic Party who chairs the parliamentary defence committee, said the news is “a relief for a mistreated and brave Ukraine”.
“The decision to approve (other countries’ requests) and supply the Leopard 2 was arduous but unavoidable,” she said.
Ms Strack-Zimmermann had been one of the loudest voices calling for a swift decision on arms supplies to Ukraine.
Two smaller opposition parties criticised the move, however.
The far-right Alternative for Germany called the decision “irresponsible and dangerous”.
“Germany risks being drawn directly into the war as a result,” its co-leader, Tino Chrupalla, said. The party, known by its acronym AfD, has friendly ties to Russia.
The Left party, which also has historic links to Moscow, warned of a possible escalation in the conflict.
“The supply of Leopard battle tanks, which ends a further taboo, potentially takes us closer to a third world war than in the direction of peace in Europe,” the party’s parliamentary leader, Dietmar Bartsch, told German news agency dpa.
Recent opinion polls show German voters split on the idea.
The pressure on Mr Scholz mounted this week after Poland formally asked Germany to approve sending Leopard 2 tanks from Polish stocks to Ukraine.
Other European nations have also indicated a willingness to part with their own battle tanks as part of a larger coalition.
Germany news weekly Der Spiegel said Berlin could initially approve the supply of one tank company, comprising 14 vehicles.
But Ukraine’s President Volodymyr Zelensky made it clear late on Tuesday that he hopes to get a more substantial number from western allies.
“It is not about five or 10 or 15 tanks. The need is greater,” he said.