Andriy Melnyk, Ukraine’s ambassador to Germany, said: “If Ukraine were in the Alliance [NATO], the risk of nuclear war would decrease.
“Then Putin would know: If Ukraine were attacked with nuclear weapons, he would have to expect a nuclear counter-attack.
“That would stop him.”
The expansion of NATO, the world’s most powerful military coalition, lies at the heart of Moscow’s motivation for invading Ukraine.
The war, though, has failed to stop the 73-year-old organisation from continuing to defend its mission – to encourage political integration on the continent.
Mr Melnyk spoke to German newspaper Funke Mediengruppe just days after Finland and Sweden submitted a formal request to become part of the group.
Ukraine LIVE: Putin plots to STARVE world
The countries’ applications were met with enthusiasm, with NATO secretary general Jens Stoltenberg saying after receiving Helsinki’s and Stockholm’s letters: “This is a historic moment, which we must seize.
“I warmly welcome the requests by Finland and Sweden to join NATO.
“You are our closest partners and your membership in NATO will increase our shared security.”
The membership process generally takes from eight to 12 months.
However, due to the threat from Russia, the two countries will potentially be members by the end of the year, as the process could be fast-tracked in two months.
According to Mr Melnyk, Ukraine’s accession to NATO could be implemented just as quickly as that of the Nordics, which are historically neutral nations.
He said: “One thing is clear – we want to join NATO quickly.
“That can happen just as quickly as in the case of Sweden or Finland.
“It would only take a purely political decision to integrate Ukraine into the Alliance quickly.”
Almost three months into a war that has killed thousands, destroyed cities and towns and triggered an exodus of nearly six million Ukrainians, Mr Melnyk has become critical of some of the West’s decisions – and in some instances, of its speed in acting.
The ambassador said he found it strange that the delivery of heavy arms to Ukraine had been repeatedly postponed.
Highlighting the generosity of the German people versus the hesitance portrayed by Olaf Scholz’s team in the dealing of the conflict, he added: “We are very grateful to the Germans, who have taken in around 700,000 of my compatriots.
“But I think these very people who are helping so generously are likely embarrassed.
“After all, they talk to the Ukrainian refugees directly, know their concerns and then probably ask themselves: Why isn’t the German government doing enough to stop this barbaric war by Russia?”
Nuclear bomb radius: How far nuclear fallout could reach [EXPLAINER]
NATO nuclear weapons mapped [ANALYSIS]
Why Putin won’t speak English – inside his bizarre power play [INSIGHT]
Mr Melnyk also called for Ukraine to be granted European Union membership within the next 10 years, after President Volodymyr Zelensky asked to join the bloc on February 28, just four days after Russia’s full-scale invasion began.
The diplomat told Funke: “Our main concern now is to obtain candidate status. Then the negotiation process can begin. That is an important political decision.”
For this, he demanded “a leading role in this historic process” from Berlin.
But on Thursday, a speech by Mr Scholz in the Bundestag dashed Kyiv’s hopes to join the 27-nation union in the wished-for timeline.
The Chancellor said he was against granting Ukraine a “shortcut” to join the EU, arguing quicker access would be unfair on countries in the Western Balkans, who have been waiting years to join.
He claimed: “The fact that there is no shortcut on the road to EU membership [of Ukraine] is an imperative of fairness towards the six countries of the Western Balkans.”
Referring to remarks by Paris that Ukraine’s EU bid could take decades, he added: “Fench President Emmanuel Macron is right to stress that the accession process is not a matter of a few months or a few years.”
In response to Mr Scholz’s speech, Ukrainian Foreign Minister Dmytro Kuleba said in a tweet: “The strategic ambiguity about the European perspective of Ukraine practised by some EU capitals in recent years has failed and must stop.”
He added the “second-class treatment” of Ukraine had “hurt [the] feelings of Ukrainians”.
Additional reporting by Monika Pallenberg