A German weapons manufacturer has said it will not be able to supply the Ukrainian government with battle tanks before 2024.

The announcement followed the United Kingdom government saying it would quickly supply tanks requested by Ukraine in a move that was seen as a first step in ensuring many more European nations start supplying offensive weaponry to the nation, instead of the mainly defensive weapons they had previously.

Armin Papperger, the chief executive of arms maker Rheinmetall, told the Bild am Sonntag newspaper: "Even if the decision to send our Leopard tanks to Kyiv came tomorrow, the delivery would take until the start of next year."

The Guardian newspaper said the company's statement will be disappointing to Ukraine and put pressure on NATO nations to find tanks and armored vehicles elsewhere that can be delivered quickly to Ukraine.

News reports in the aftermath of the UK's announcement that it would send tanks to Ukraine suggested Germany's Rheinmetall had 22 Leopard 2 tanks and 88 older Leopard 1 tanks in its warehouses, raising hopes among Kyiv's allies that they could be quickly sent for use in the Russia-Ukraine conflict.

But Papperger's assertion that their preparation will take many months, and cost hundreds of millions of euros that the company was unwilling to spend, ended thoughts of a quick delivery.

"The vehicles must be completely dismantled and rebuilt," he said.

Jens Stoltenberg, NATO's secretary-general, said on Sunday Ukraine's Western allies will ensure the country soon gets an influx of heavy weapons, including artillery and missiles.

"The recent pledges for heavy warfare equipment are important — and I expect more in the near future," he told Germany's Handelsblatt daily newspaper.

Ukraine's President Volodymyr Zelensky hailed the UK's commitment to send 14 Challenger 2 tanks, saying on Twitter it will "send the right signal to other partners".

Poland has also said it will send a company of Leopard tanks to the country — likely 14 vehicles-"as part of international coalition building".And the United States also recently said it will send 50 Bradley tank-killing armored vehicles.

Sky News said on Monday the UK's Challenger 2 tanks could be on the ground in weeks.

London also recently said it will send around 30 AS90s — large, self-propelled guns — to the country.

Ukraine's allies had previously held back on supplying offensive weaponry over fears it would escalate the situation. Russia's embassy in the UK said "the increasingly obvious involvement of London in the conflict" will only prolong it and cause more death and destruction.

A spokesman told Sky News: "As for the Challenger 2 tanks, they are unlikely to help the armed forces of Ukraine turn the tide on the battlefield, but they will become a legitimate large target for the Russian artillery."