Vladimir Putin to leave G20 early after 'tense' meeting with David Cameron

Vladimir Putin is set to leave the G20 summit early after a tense meeting with David Cameron over Moscow's actions in Ukraine.

The Russian president is reportedly planning to leave the summit early on Sunday and miss its official lunch in response to repeated criticism from western leaders.

The move comes after Tony Abbott, the Australian Prime Minister, threatened to "shirt front" Mr Putin - a form of physical confrontation. Stephen Harper, the Canadian Prime Minister, told Mr Putin: "I guess I'll shake your hand, but I'll only have one thing to say to you - get out of the Ukraine."

Mr Cameron told Mr Putin that he is at a "crossroads" and could face further sanctions after the pair held "robust" discussions on Ukraine.

During a tense 50 minute meeting Mr Cameron warned that Russia is risking its relations with the West and must end its support for Russian separatists.

Mr Putin denied that Russian troops have entered Ukraine and claimed that he is prepared to accept a ceasefire and stop the flow of Russian weapons across the border. He also said that he is prepared to recognise Ukraine as a "single political space".

Mr Cameron is said to be "realistic" about Mr Putin's comments after he previously broke pledges to end Russian action in Ukraine.

The meeting at the G20 summit in Brisbane, Australia, follows a tense build up in which Mr Cameron compared Russia to Nazi Germany.

Tensions escalated further when Russia stationed a fleet of warships off the coast of Australia in an apparent show of strength ahead of the summit.

In interviews hours before the meeting, Mr Cameron suggested that he cannot trust Mr Putin and described Russia's decision to send a fleet of warships to Australia as "international machismo".

Asked if he trusts Mr Putin, the Prime Minister told ITV News: "I take people as I find them. The sad thing is that to date undertakings given in the Minsk agreement have not been followed but the right thing to do is to continue to engage.

"So far we haven't seen his actions follow up the statements that he's given on previous occasions.

"The point is and the reason for meeting is that this issue matters and it's very important Russia understands what's at stake and gets a very clear message.

"There's a real choice here, there's a different and better way for Russia to behave that could lead to an easing of relations, but at the moment he's not taking that path."

During the meeting Mr Cameron said that he and Mr Putin have to "agree to disagree" on several areas, including Mr Putin's continued claims that the uprising against the former Ukrainian president was illegitimate.

Mr Putin still insists that Russian troops have not crossed the border into Ukraine, despite evidence to the contrary. The Prime Minister said that drones should be deployed to monitor the situation on the ground, a move which Mr Putin claimed he supported.

The West is now considering further sanctions, although further "sectoral" sanctions against other parts of Russia's economy are unlikely next week. At present the West has imposed sanctions on the energy, defence and banking sectors.

Instead it is more likely that the West will increase the number of individuals who are subject to the sanctions in coming weeks.

Mr Cameron also raised the prospect of a "national unity government" in Syria to replace Bashar al-Assad's dictatorship. He highlighted how the conflict is threatening both Britain and Russia.

A Kremlin spokesman said that Mr Putin and Mr Cameron addressed the "fundamental causes of the current breakdown of relations" between Russia and the West.