Thousands of soldiers could be sent to the Russian border by Nato as tensions with Vladimir Putin increase.

Bosses of the North Atlantic Treaty Organization are considering placing troops across Poland and three other Baltic states, according to sources quoted in the Wall Street Journal.

Tensions have been ramped up ever since Russia annexed Crimea from Ukraine last year.

The development has thrown Ukraine into a chaotic state of civil war.

Former US Ambassador to Ukraine Steven Pfifer said that reports of Nato considering sending soldiers is a sign that Russia is now viewed "not as the partner we'd hoped for over the past 20-odd years, but more as a potential adversary".

He added: "You're starting to turn the ship.

"If you're talking 800 to 1,000 troops, that would be big.