SABRA LANE, PRESENTER: Until July this year, Australia and Ukraine didn't have much in common. But the Malaysia flight MH17 disaster, which claimed 298 lives, brought the two together in ways never imagined. The two countries united to apply maximum pressure for access to the crash site, to recover the wreckage, remains and clues to pinpoint who's responsible.

Ukraine's President, Petro Poroshenko, who is visiting Australia, says he knows who's to blame, accusing so-called "terrorists", he says, of occupied eastern Ukraine. The conflict's choked off supplies of coal, crucial for his nation's power generation, and he's hoping Australian uranium might help fill the void. I spoke with the President earlier in Canberra.

President Poroshenko, thank you very much for talking to 7.30.

PETRO POROSHENKO, UKRAINIAN PRESIDENT: Thank you very much for the invitation.

SABRA LANE: You've indicated that you would like to buy uranium from Australia. How much and how soon would you like to buy uranium?

PETRO POROSHENKO: We just launched this project for the building of the energy - not independence, but at least diversification. After what's happened with the coal supply, gas supply, for us, as a country who has more than 60 per cent of the electrical energy produced by our station, we produce on nuclear station, and beforehand we were connected only with a Russian one, we should find out steps how to make us more energy diversified. I think that would be a good idea if you find out an opportunity to use Australian uranium for our nuclear station.

SABRA LANE: It's fairly urgent for you. A lot of your plants do rely on coal from an area now that's in dispute.

PETRO POROSHENKO: I think - I hate the idea to have anything urgent in nuclear energy. So better to have security and reliability. But I think it's high time to launch this process.

SABRA LANE: Many Australians would be a little bit concerned that Australia would be talking to Ukraine about providing uranium, given the uncertainty in your country right now, given the conflict involved. Could you give a guarantee that that material won't fall into the wrong hands and that it will be used for civil purposes only?

PETRO POROSHENKO: We are a country who has before the third nuclear arsenal in the world. Exactly 20 years ago, we voluntarily gave up this third nuclear arsenal in exchange for the security guarantee we receive from United States, United Kingdom, ...

SABRA LANE: And Russia?

PETRO POROSHENKO: ... France, China and Russia. Now Russia is not - is an aggressor on our territory.

SABRA LANE: 20 years ago Ukraine did give up its nuclear arsenal. There are some people who wish that Ukraine had hung on to it, given what's happening now. Do you ever harbour that desire again, to be a nuclear power?

PETRO POROSHENKO: No. This would be absolutely irresponsible. Believe me that the strongest security in the modern world in the 21st Century supply, but not nuclear power. This is technology from the 20th Century. We can win the aggressor only when we will be united and when the whole world demonstrates exactly what we have now: solidarity with Ukraine.

SABRA LANE: We've just been talking about trade. Australia's relationship with Ukraine is more than trade. We've been brought together by the Malaysian MH17 disaster. Where is that investigation at now?

PETRO POROSHENKO: The leading countries, the Dutch specialist, we have a very positive co-operation experience and the preliminary results is already delivering the information that the attack was done from the territory controlled by the terrorist sponsored by Russians. The surface-to-air missile which were delivered from Russia and we have a satellite photo of this rocket launch.

SABRA LANE: But the Dutch preliminary investigation didn't finger anybody, it didn't blame anybody in particular. It said that the aircraft had been hit at a high velocity by - it had been peppered by material, but it didn't identify anybody responsible.

PETRO POROSHENKO: This is not published yet; preliminary results. Believe me, the - all the specialist are unanimous about the person responsible - not person, but the side responsible for the - this disastrous attack. And I'm really hope that the first half of the next year, the results will be published and that will make it necessary for the immediate action for bring the responsibility to those who make this attack.

SABRA LANE: You say terrorists are responsible; who?

PETRO POROSHENKO: Russian-led terrorists who occupied territory of the Donetsk and Luhansk region of Ukraine. Their - these weapons, state-of-art, very sophisticated, modern weapons, were supplied by Russia.

SABRA LANE: You seem to have a really good rapport with Tony Abbott.

PETRO POROSHENKO: I really admired how the Australian demonstrate the solidarity with Ukraine. And the - this tragedy, again, make us much closer than before.

SABRA LANE: What did you think of Tony Abbott when he said he was going to shirtfront the Russian President?

PETRO POROSHENKO: He's a great state leader. I think that - he's very responsible. And I think that the way how he organised the G20 in Brisbane help us a lot to be closer to the peace deal.

SABRA LANE: The pro-Russian separatists say they don't want to give up. How is this going to come to a resolution?

PETRO POROSHENKO: These terrorist are presented nobody. And how we can find out the way out from this situation is just stop the war and launch the political process.

SABRA LANE: Well, there've been many Western leaders who have said very strong things - the leader of Canada, leaders of the United States, the United Kingdom, our Prime Minister, but words to this day don't seem to have had much of an impact.

PETRO POROSHENKO: Why are you - why you are so pessimistic? This is absolutely not true, believe me, because the sanction which is co-ordinated, presented by Western leaders, is working.

SABRA LANE: Do you have enough confidence in the United Nations, especially the Security Council, given that Russia is one of the permanent members?

PETRO POROSHENKO: Look, we should understand, we should be absolutely frank and straightforward: the conflict on the east of Ukraine demonstrate the uneffectiveness of the post-War global security system, including the Security Council of the United Nations. And it happen if one of the permanent member who has a veto right is an aggressor. We should develop the new system who can stop this very dangerous development of the situation in the whole world.

SABRA LANE: How could the Security Council be changed to be more effective in your view?

PETRO POROSHENKO: I doubt that we are ready now to discuss publicly the way how the Security Council should be changed. Maybe we should withdraw the veto right from the permanent member.

SABRA LANE: Do you think the world has entered a new form of cold war?

PETRO POROSHENKO: No, this is not a cold war. But - because of the fact that this is not a cold war, it's not become less dangerous. But I am an optimist and I am an optimist because of the fact that the global unity are existing. I am a president of peace, I am not a president of war. Ukraine is a country of peace, not a country of war. And co-ordinated efforts over the international community is bring situation to the peace, not to escalate the war.

SABRA LANE: You said I'm a pessimist, you're on optimist. When do you think you'll have your peace?

PETRO POROSHENKO: Look, it can happen tomorrow. Why I'm an optimist also that if we will have a ceasefire, the people will see that they don't need the people with their arms, with their machine guns on the street. They simply bring them an opportunity to come back to the normal life. We win this war.

SABRA LANE: President, I think most of the world have their fingers crossed as well. Thank you very much for your time.

PETRO POROSHENKO: Thank you.