First of two vessels due for delivery this month will not be handed over until military action in Ukraine ceases

France will not hand over the first of two state-of-the-art warships built for the Russians until Moscow halts its military action in Ukraine, the Elysée Palace has announced.

The Vladivostok has been undergoing sea trials with a Russian crew in the French Atlantic port of Saint-Nazaire and was due to be officially delivered this month.

However, Paris announced that the deal, which was opposed by the US and Russia’s Baltic neighbours and put on hold during the Ukraine crisis, was suspended until further notice.

A statement said the French president, François Hollande, “considers the current situation in the east of Ukraine still does not allow for the delivery of the first BPC [control and command vessels]. [He] therefore considers it appropriate to suspend the authorisation of the delivery until further notice.”

A second Mistral-class assault vessel, the Sevastopol, named after the Black Sea port in Crimea that has been annexed by Moscow, was due for delivery next year.

Two weeks ago a Russian official threatened to sue France for breach of contract, warning of “serious repercussions” if it did not hand over the Vladivostok by the end of November.

On Tuesday, Yuri Borisov, Russia’s deputy defence minister, rowed back from this hard line. He told the state news agency Ria Novosti that Russia would hold off from any international legal action “for the moment”.

Borisov said Russia would “wait with patience”. “Everything is specified in the contract, and we will act under that contract, just like all civilised people do,” he said.

Earlier this year the French foreign minister, Laurent Fabius, said the deal would go ahead, declaring that it had to be honoured like all signed and sealed contracts.

On Tuesday, following an escalation of Russian military action to support separatists in Ukraine, Fabius also appeared to have changed tack. He told France Inter radio that the conditions for delivering the first of the warships had not been met.

Thierry Mariani, an MP with the opposition UMP, criticised the Elysée’s decision. “It’s a deplorable saga in which France is not taking a firm decision. We are in the process of creating a false suspense … What we seem to be forgetting in all this is that we have a contract with Russia. In this case, we have above all given in to pressure from our American, Baltic and Polish friends.”

The €1.2bn deal to supply Russia with two Mistral vessels was concluded in 2011 by the then president Nicolas Sarkozy. Since September his successor Hollande has argued that the ceasefire in Ukraine must be “entirely respected” before Paris will hand over the Vladivostok.

The 180-metre, 22,000-tonne Mistral class vessels are capable of carrying 16 helicopters, four landing craft, 60 armoured vehicles, 13 battle tanks and between 450 and 700 soldiers for up to six months, and will give the ageing Russian naval fleet a new lease of life.

The Russians have taken an option on a further two Mistral warships. The rear half of the Vladivostok was built in a Russian shipyard at St Petersburg and towed to France for assembly.

In 2008, Vladimir Vysotsky, head of the Russian navy, said his forces would have been victorious in Georgia “in just 40 minutes” if his Black Sea fleet had had the French warships. Shortly afterwards, Putin said during a visit to Paris: “I can assure you that if we purchase this armament, we will use it wherever deemed necessary.”