Sharjah 24 – AFP: Russia risks becoming embroiled in a "terrible quagmire" if it invades Ukraine, British Foreign Secretary Liz Truss is to warn Friday in a speech in Sydney.

The UK's top diplomat will tell Russian President Vladimir Putin that he is on the brink of making a strategic blunder by launching military action and "has not learned the lessons of history."

According to prepared remarks to the Lowy Institute, Truss will urge Putin to "desist and step back from Ukraine before he makes a massive strategic mistake."

"Invasion will only lead to a terrible quagmire and loss of life, as we know from the Soviet-Afghan war and conflict in Chechnya."

Tens of thousands of Russian troops have massed on Ukraine's border, and the drumbeat of invasion has been growing for months.

Few military experts believe that Kyiv's smaller forces could repel an outright invasion.

But Truss will become the latest official to raise the spectre of a protracted and bloody Ukrainian resistance that ensnares occupying Russian forces.

The top diplomat is currently on an official visit to Australia alongside British Defence Secretary Ben Wallace.

Speaking in Sydney at the conclusion of the talks, Wallace and his Australian counterpart Peter Dutton drew a parallel between rising tensions today and the pre-war 1930s.

Truss will urge allies to "step up" in the face of the crisis, linking the Ukraine conflict to a slew of increasingly emboldened authoritarian regimes who are looking to "export dictatorship."

"Together with our allies, we will continue to stand with Ukraine and urge Russia to de-escalate and engage in meaningful discussions. What happens in Eastern Europe matters for the world," she will say.