The Ukrainian president has said he has evidence that Russian military tanks are massing along his country's border.

Petro Poroshenko has shown Sky News images of what he claims are tanks lining up along the border, close to where Russia stores its ammunition.

He said: "This is the tank base just 18km from our border, this was happening in September, October, and now.

Image: Mr Poroshenko says the tanks have been building up since September

Image: Mr Poroshenko calls the captured sailors as 'prisoners of war'

"This is 18km from my border, this is the same warehouse where they have their ammunition, the same where they have multi-rocket launch systems, we should be prepared to protect my country.

"If the whole world has no reason to trust Putin, Ukraine definitely doesn't have a reason to go with him."


In full: Poroshenko on 'evidence' of Russian tanks lining up along the border

He also used the interview to appeal for help from Western leaders.

:: Putin accuses Ukraine leader of staging Black Sea clash to boost popularity

Image: Mr Poroshenko says he is ready to defend Ukraine

Mr Poroshenko said: "There is no red line for Putin and this is the very strong reason why we should be together, the whole civilised world.

"Not only the leaders, with whom [we have] a very reliable partnership, but the people of UK, of Europe, USA, Canada, Australia, Japan, the whole civilised world would be together and this is very important for global security."

His comments come amid rising tensions between the two former Soviet neighbours.

Russia seized three Ukrainian navy ships and their crew in the Kerch Strait after accusing them of venturing into their territory.

Russia is continuing to block the strait and refuses to free the Ukrainian sailors.

Mr Poroshenko referred to the captured sailors as "prisoners of war" and called on Mr Putin to release them, asking for pressure from the international community to encourage this.

:: Russia-Ukraine crisis: Captured sailors shown on Russian TV

Ukraine rejects the charge that they were trespassing in Russian waters and said that two of its ports in the Azov Sea are effectively under blockade by Russia.

Mr Poroshenko said Russia is "strangling" Ukraine with ongoing restrictions.

Image: The Ukrainian president says Russian tanks are massing on the edge of his country. File pic

He said: "They want to hit Ukraine because through Azov Sea, and our sea ports, we export about 40% of our industrial production.

"This is another step for a Russian organised embargo, only buying Ukrainian goods, switching off the natural gas, this is part of the hybrid war that Russia want to attack us."

Moscow denies restricting any shipping.

Martial law has been imposed in some parts of Ukraine over the crisis.

Donald Trump cancelled his meeting with Mr Putin at the G20 amid the ongoing situation with Ukraine. However the Kremlin responded by saying it would mean Mr Putin would have more time for "useful meetings".