AMSTERDAM (Reuters) - The Dutch government is seeking the United Nations' support to set up a tribunal to identify and try those responsible for shooting down a Malaysia Airlines plane over territory held by pro-Russian separatists in eastern Ukraine a year ago, Prime Minister Mark Rutte said on Friday.

Mr Rutte said a UN tribunal would give "the best guarantee of cooperation from all countries" in seeking justice for the families of 298 victims, most of whom were Dutch passengers aboard flight MH17.

Mr Rutte's comments confirmed a report by Reuters last month that the Netherlands was seeking to establish such a tribunal.

Malaysia told the United Nations Security Council on Thursday it plans to push for the tribunal, though Russia described the move as premature, diplomats said.

Malaysia Airlines flight MH17 was shot down in July last year. It crashed in territory held by Russian-backed separatists.

Ukraine and Western countries accuse the rebels of shooting it down with a Russian-made missile. Russia has rejected accusations it supplied the rebels with SA-11 Buk anti-aircraft missile systems.

"Malaysia briefed the council members this morning of their intention to present a resolution in relation to MH17," said New Zealand's UN Ambassador Gerard van Bohemen, president of the UN Security Council for July.

"They are seeking to find a mechanism to deal with criminal accountability in relation to the downing of the aircraft," he said, adding that it is a joint proposal by Malaysia, Australia, the Netherlands, Belgium and Ukraine.

Diplomats, speaking on condition of anonymity, said Russia described the proposal as premature and believed the council should wait for the results of other investigations. Russia's UN mission declined to comment to Reuters on the proposal.

Russia is a veto-wielding power on the 15-member council, along with France, Britain, China and the United States, and therefore has the option of blocking the proposal if it is put to a vote.

The Netherlands has taken the lead in an a multinational investigation into the crash. Malaysia, Australia, Belgium and Ukraine are also part of the joint inquiry.

Russian investigators have also been looking into the crash. "I expect that issue to be the subject of quite intensive consultations in the course of the coming months," Mr van Bohemen told reporters. He said Malaysia had not yet circulated a draft resolution.