Australia to send military trainers and advisers to help Ukraine.

This is understood to take the form of Australian Defence Force personnel who will train and advise the Ukrainian military - a clear signal that Mr Abbott is pushing to position Australia firmly as an active "middle power" in international affairs.

But just hours after Mr Abbott made his announcement, Ukrainian President Petro Poroshenko declared he had reached a ceasefire deal with Moscow, though whether this will end the fighting with pro-Kremlin rebels in the country's east remains unclear.

Less than two months after the downing of Malaysia Airlines flight MH-17 and with more than 1000 Kremlin troops flooding across the border into Ukraine in recent weeks, Mr Abbott made it clear Australia was getting firmly in Ukraine's corner over its rising tensions with its giant, nuclear-armed neighbour.

"The government and, I believe, the Australian people, would like to repay Ukraine for its support and friendship, especially as Ukraine continues to be subject to active destabilisation and indeed outright invasion from Russia, a country it has never, ever sought to harm," he said.

More immediately, Australia will provide "non-lethal military assistance" to Ukraine, such as military winter clothing, blankets and first-aid kits. It will also establish an embassy in the capital, Kiev. Mr Poroshenko said he had spoken with Russian President Vladimir Putin and the conversation "resulted in an agreement on constant ceasefire in the Donbas" - referring to eastern Ukraine, including the Donetsk region.

NATO has recently reported that at least 1000 Russian troops, as well as tanks and other equipment, had cross the border into Ukraine.

Australian government sources said the military training and advice would aim to build up the Ukrainian military as an institution and could include logistics training, legal training - indicating issues such as rules-of-engagement for troops in conflict - and English-language training. But this leaves open the possibility of further, more substantial training. It is understood that will begin in coming months. Mr Abbott said the assistance would be provided in co-operation with European partners and allies.