Cabinet minister Malcolm Turnbull has ramped up pressure on Vladimir Putin over the MH17 disaster. Courtesy Today/Channel Nine

THE one person who knows what happened to Malaysia Airlines Flight 17 is the Russian president and he must reveal what he knows, the Australian government says.

Cabinet minister Malcolm Turnbull has ramped up pressure on Vladimir Putin over the disaster, before the leader’s arrival in Brisbane for the G20 summit later today.

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Mr Turnbull repeated Prime Minister Tony Abbott’s call for an apology from President Putin over the loss of 298 lives, including 38 Australians, when the plane was shot down over eastern Ukraine in July.

“He should set out those facts, take responsibility, express his compassion and his condolences and apologise for this terrible event,” the minister told the Nine Network.

“The one person who knows exactly what happened is Vladimir Putin.”

Opposition foreign affairs spokeswoman Tanya Plibersek said the families grieving for their lost loved ones needed answers.

“It’s not about what the Australian government needs, it’s about what the families of those who lost their lives need.”

Meanwhile, Mr Turnbull played down the presence of Russian warships in international waters off Australia, saying it’s no cause for alarm.

The government has previously said such movements are not unusual when significant international events like the G20 are underway.

Four Russian warships are conducting exercises off the northeast of Australia in a move that has been interpreted - but not confirmed - as a show of force by President Putin.

Australia has sent at least two, and possibly a third naval vessel to the area, to monitor the Russian fleet. AP-3C Orion aircraft are also conducting maritime surveillance patrols.

“This is all very normal. This is what navies do,” Mr Turnbull said.

“We should not be worried at all.”

The Russian embassy explained its presence off Australia by saying it’s testing its Pacific fleet’s range capability, in case it has to do climate change research in the Antarctic.

It also said the fleet could, if necessary, provide security for the Russian president.

President Putin will arrive in Brisbane on Friday evening, rounding out a full day of leader arrivals for the global summit being chaired by Australia.

Mr Abbott is also due in the Queensland city on Friday alongside British Prime Minister David Cameron, after the British leader addresses parliament in Canberra.