A ban on Ukraine joining Nato is a key condition of Russia accepting any terms of a ceasefire deal, it has emerged. America is trying to broker a truce between the warring countries which would start with a 30-day ceasefire.

But the plan has so far been dismissed by Moscow with Vladimir Putin seen yesterday in military fatigues as he visited troops in Kursk. Russia holds just under one-fifth of Ukraine and has so far refused to enter peace talks with Kyiv. It has now emerged no progress will be made unless guarantees are given that Ukraine will be blocked from joining Nato – the North Atlantic Treaty Organisation – which was formed in 1949.

The Kremlin also wants recognition of Russia‘s claim to Crimea and four Ukrainian provinces and an agreement that foreign troops not be deployed in the country.

Nato’s primary purpose was to block expansion in Europe by the former Soviet Union – the group of communist republics headed by Russia. Membership rules state that if one is attacked, all others help defend it.

Nato does not have its own army, but military action by member countries is taken as a collective response.

The UK, US, France, Belgium, Canada, Denmark, Iceland, Italy, Luxembourg, the Netherlands, Norway, and Portugal were the 12 founding countries.

The club now has 32 members across Europe and North America, including, after the Soviet Union fell in 1991, Eastern European countries Albania, Bulgaria, the Czech Republic, Estonia, Hungary, Latvia, Lithuania, Poland, Romania and Slovakia.

Bosnia and Herzegovina and Georgia have also asked to join.

In 2008, the alliance said Ukraine could eventually come into the fold, but Russia has vocally opposed the idea, fearing it would bring Nato forces within touching distance of its heavily protected borders.

After Russia‘s invasion in 2022 Ukrainian President Volodymyr Zelensky demanded membership be fast-tracked but was told approval would be given only after the war ended.

He said he was prepared to “give up” his presidency if it meant Ukraine could join Nato, saying: “If to achieve peace you really need me to give up my post, I’m ready. I can trade it for Nato membership, if there are such conditions.”

Earlier this year US President Donald Trump urged Nato’s European members to spend 5% of their national income – or GDP – on defence, saying: “They can all afford it.” Nato secretary-general Mark Rutte has also urged member states to boost defence spending.

This week President Trump agreed to resume weapons supplies and intelligence sharing with Ukraine after Kyiv said it was ready to support a ceasefire proposal.

US Secretary of State Marco Rubio said he hoped a deal could be struck within days and Europe would have to be involved in any security guarantee for Ukraine, adding: “Here’s what we’d like the world to look like in a few days: Neither side is shooting at each other, not rockets, not missiles, not bullets, nothing…and the talking starts.”

But the sight of Putin dressed in camouflage in Russia’s Kursk Oblast region, which includes the disputed territory of Crimea, has ratcheted tensions further and made imminent progress unlikely.

The despot fuelled tensions further by saying captured Ukrainian troops ought to be “treated as terrorists, in accordance with the laws of the Russian Federation”.

The Kremlin also rejects proposals for European peacekeepers to be stationed in Ukraine after any peace deal is struck, as has been proposed, claiming the population “would be under serious Western influence”.