Russia under pressure at G20 summit over Ukraine

Russia has been rebuked by Western leaders about its role in the Ukraine crisis, at a G20 summit in Australia.

Canadian PM Stephen Harper told Russian President Vladimir Putin that Russia needed to "get out of Ukraine".

US President Barack Obama said Moscow's "aggression" in Ukraine was a "threat to the world", while Britain threatened more sanctions unless Russia stopped "destabilising" its neighbor.

The two-day summit in Brisbane is focusing on promoting economic growth.

World leaders are expected to expand on plans agreed by G20 finance ministers in February to boost global growth by 2% in five years.

FROSTY HANDSHAKE:

However Saturday - the first of the two-day summit - was dominated by Ukraine, where pro-Russian separatists have been fighting government forces in eastern regions.

Ukraine and its Western allies have accused Russia of sending military forces across the border, something the Kremlin denies.

The EU imposed sanctions when Russia annexed Crimea in March and has added further measures since.

Before the G20 summit began, UK Prime Minister David Cameron said there would "have to be a very different relationship" between Europe and Russia if "we continue to see Russian troops" inside Ukraine, adding that there was "the potential for further sanctions".

Cameron later held a private meeting with  Putin. The two discussed "rebuilding relations",  Putin's spokesman Dmitry Peskov said.

The Russian president faced a frosty reception from Canadian Prime Minister Stephen Harper.

"I'll shake your hand, but I only have one thing to say to you: you need to get out of Ukraine,"  Harper told him, the Canadian leader's spokesman said.

President Obama said the US was at the forefront of "opposing Russia's aggression against Ukraine, which is a threat to the world".

Russian officials said  Putin was planning to leave the summit on Sunday ahead of schedule, but gave no reasons for the move.

Meeting on the margins of the summit on Saturday,  Putin urged his French counterpart Francois Hollande to join him to defuse tensions between the two countries over Ukraine.

France has withheld the delivery of two warships to the Russian navy over its actions in Ukraine.

Opening the summit, Australian Prime Minister Tony Abbott said he wanted to use the event to reassure people about the direction of the world's economy, with a "message of hope and optimism".

He said job creation, identifying tax cheats and strengthening the global economy would all be discussed.

His government had tried to keep climate change off the agenda, despite calls from campaigners.

WHAT IS G20?

The "Group of Twenty" represents two-thirds of the world's population, 85% of global GDP and over 75 percent of global trade.

It began in 1999 as an annual meeting for finance ministers and central bank governors following the Asian financial crisis, before evolving to also include a summit for countries' leaders in 2008, after the global financial crisis.

G20 meetings are aimed at deepening economic co-operation and strengthening the global economy.

It comprises 19 countries and the European Union.

At each meeting, the host country invites non-member guest countries to attend. For 2014, Australia has invited Spain, Mauritania, Myanmar, Senegal, New Zealand and Singapore.