Foreign Affairs minister Julie Bishop has confirmed there were 27 Australians on board the Malaysia Airlines plane believed to have been shot down.

Foreign Minister Julie Bishop says 27 Australians were on the Malaysia Airlines flight downed in Ukraine.

“I can confirm 27 passengers on that flight were Australian nationals,” she said.

“We’ve been able to independently verify that.”

She said Australian officials were seeking permission to access the crash site, which was in rebel held territory in eastern Ukraine.

She said Australia would demand a full, independent international inquiry into the crash, amid reports Russian separatists have taken the plane’s black box.

“Regardless of the circumstances we urge the separatists to co-operate with an investigation into this crash,” Ms Bishop said.

“If they have taken the black box it must be returned to authorities immediately.”

She said cabinet’s national security meeting would convene shortly to discuss the disaster.

“This incident underlines the urgent need to de-escalate tensions in eastern Ukraine,” she said.

She said the flight was connecting to Australia, and that explained why so many Australians were onboard.

Ms Bishop promised grieving families the Australian victims would be brought home.

“We will do everything possible to ensure we can bring home those Australians who were on board that tragic flight.”

Ms Bishop said the nationalities of all those on the plane had not yet been determined.

“… so the final number may be higher,” she said.

She said she’s spoken with the foreign minister of the Netherlands.

She said Prime Minister Tony Abbott would shortly also speak to the prime minister of the Netherlands.

“This is a terrible tragedy. We don’t know the cause but there is speculation that the plane was shot down.

“If that is the case it is an unspeakable crime.”

Ms Bishop said it was too early to point the finger of blame, and it was too early to say if Russian President Vladimir Putin would be welcome to attend the upcoming G20 summit in Australia.

“It’s too early to say but we are taking this exceedingly seriously, (with) the utmost seriousness,” she said.

Ms Bishop said the Australian government was mobilising staff from across Europe to help respond to the tragedy.