A woman places a candle during a demonstration of solidarity with Ukrainian people in front of the Ukraine embassy in Warsaw
A woman places a candle during a demonstration of solidarity with Ukrainian people in front of the Ukraine embassy in Warsaw February 19, 2014. Reuters/Kacper Pempel

Australia has announced it is mulling to ban sales of uranium, the chemical element used to make atomic or nuclear power, to Russia given the continuing rise of tensions with it and Ukraine.

Recently, the North Atlantic Treaty Organization (NATO) reported seeing the presence of 20,000 combat-ready Russian troops on Ukraine's eastern border. NATO said it does not believe the troops' presence had something to do with a "humanitarian or peace-keeping mission" and insinuated it could be a prelude to war between the two nations.

Read: World War III Triggers: Russia Invasion of Ukraine Looms, 20,000 Troops on Border - NATO

Australian Prime Minister Tony Abbott said Moscow has been advised of the proposed uranium ban. "Everything's on the table," he said.

"Our message to President (Vladimir) Putin is, 'hold your forces back'," Mr Abbott said. "Any move by Russian forces across the border would be an invasion, pure and simple...

"The business of Ukraine should be left to Ukrainians to sort out."

Read: Casualty of EU Sanctions: Low-cost Russia Airline to Suspend Services; Russia Counters, to Ban European Carriers from Airspace

This, as NATO over the weekend sent out a plane to Ukraine carrying US$4.5 million worth of non-lethal military equipment.

The artillery, which includes helmets, ballistic eyewear, protective vests, first aid kits, tents, and sleeping bags, will help Ukraine "protect its eastern border against Russian aggression," Canadian Prime Minister Stephen Harper said in a statement. The items were delivered by a Canadian CC-130J Hercules plane.

He stressed the request for such equipment was made by the Ukrainian government itself. "Ukraine has asked for this," Defence Minister Rob Nicholson Nicholson said at the Canadian Forces Base in Trenton.

Anders Fogh Rasmussen, NATO Secretary-General, said the organization will teach Ukraine defense planning during planned joint exercises.

Meantime, Mr Abbott said the G20 members have not discussed if Russian president Vladimir Putin should be banned from the G20 summit in Brisbane scheduled three months from now.

"My hope is that, even at this late stage, Russia will wake up to itself," he said.

"[I hope] it will realise that what's being done in the eastern Ukraine is destabilising a country which should be free to determine its own place in the world - that Russian-backed separatists are wreaking havoc in eastern Ukraine."