Vladimir Putin plans to build a 450-mile railway from Russia to Crimea in an attempt to create a back-up supply line for troops in case the Kerch bridge is destroyed.

The Russian president told a crowd of supporters on Monday that he would make sure the new railway, which runs through occupied Ukraine, will soon be operational.

“I have just been informed that the railway from [Russian] Rostov-on-Don to Donetsk, Mariupol and Berdyansk has been rebuilt,” he said.

“We will continue this work, and soon trains will ride all the way to Crimea, and this will be another alternative route, in addition to the Crimean bridge.”

The creation of the railway route, he told the rally, will “make us genuinely stronger”.

It is not clear how much work has been done on the route, details of which first emerged in Russian-language media late last year. Officials hailed the scheme’s potential military and economic benefits.

Yevgeny Balitsky, the Russia-appointed head of occupied parts of Zaporizhzhya said: “By building a railway line – even a one-track one, we will solve the problems of the military. And more importantly, we will solve the issue of exporting grain, iron ore, coal and other commodities onto the mainland.”

Mr Balitsky on Tuesday said the new railway mentioned by Mr Putin will be routed to make it less vulnerable to Ukrainian shelling.

He appeared to contradict Putin’s claim that work on the railway was complete, saying the line is still under construction and is set to be completed by the end of summer.

Putin, who after claiming a landslide victory in Russia’s sham presidential election will now stay in power until at least 2030, did not reveal how much the project will cost.

State spending on the war and various war-related projects has been propping up the Russian economy amid an exodus of major international businesses from the country.

Accessing Crimea, illegally annexed by Russia in 2014, was a source of major problems for the Kremlin until a multi-billion dollar, 12-mile bridge linking it to the Russian Black Sea coast was inaugurated in 2018.

Russia seized swathes of southern and eastern Ukraine in the first months of the 2022 invasion, creating a “land bridge” to Crimea.

But Ukraine has attacked and severely damaged the Kerch bridge twice since the full-scale invasion. Road and rail traffic across the bridge are frequently disrupted by the threat of further Ukrainian attacks.

Ukrainian officials have made it clear that they consider the bridge a legitimate target and will strike it whenever they can.

The bridge has been a major supply artery for the Russian military in southern Ukraine, allowing them to rapidly move troops and ammunition from southern Russia to the front lines.

Russia stopped using the Soviet-era railway linking southern Russia and southern Ukraine in Zaporizhzhya as it was too close to the front line and came under frequent attacks.

Sergei Aksyonov, the head of Russia-occupied Crimea, on Tuesday welcomed the idea of a railway link through occupied southern-Ukraine, saying it would offer more economic opportunities for the region.