Ukraine's President Petro Poroshenko (C) signs the visitor's book as his wife Maryna (R) looks on during their visit to the Australian War Memorial in Canberra. Source: AFP

Tony Abbott and Mr Poroshenko have visited a crisis management centre at the Department of Foreign Affairs and Trade to thank Australian officials involved in the aftermath of the MH17 tragedy.

Mr Poroshenko said he was “deeply touched” by the chance to meet the men and women who helped in the investigation and clean-up, and took the time to shake each of their hands.

The meeting coincided with the announcement of Australia’s first resident Ambassador to Ukraine, Doug Trappett.

Mr Trappett, a career officer at DFAT, will facilitate “continued cooperation” between Australia and Ukraine, including on the MH17 investigation.

The Prime Minister also announced the extension of visitor visas to Ukrainian nationals in Australia, given the “continued unrest” in the country.

Ukrainians will be able to apply for an extension of their visa for a further six months.

Mr Poroshenko, who told the Australian officials there was a time when he and Mr Abbott spoke daily, said he wanted the MH17 investigation completed “as soon as possible”.

“We don’t see any excuse to postpone and to delay the investigation results,” he said.

“Those who should be responsible for the terrorist attack ... the world has the right to know their names.”

He said the Donetsk People’s Republic and Lugansk People’s Republic must be labelled terrorist organisations.

“This is a global threat and in the course of this painful experience our joint common efforts have (brought) our nations much close together,” Mr Poroshenko said. “(We are) so far away from each other but our hearts become much closer.”

Mr Abbott praised Mr Poroshenko’s “strength of character”, saying “whenever I am tempted to think that my job is difficult, I think of the work you have to do”.

“I don’t envy you your job Petro,” he said.

“You are presiding over a country in transition. You are engineering an economic institutional and political transformation and you are doing it in the face of a deadly external threat.

“I can’t think of any head of government anywhere in the world right now faced with greater challenges but I can’t imagine anyone facing up to those challenges with more courage.”

Mr Abbott thanked the Ukrainian President for the country’s friendship “shown to us in this whole episode”.

“And for the friendship which I believe will now persist between our countries for years and hopefully decades to come,” he added.

The Prime Minister told the officials gathered at DFAT they “epitomise Australia at its best” and commended their quick response to the tragedy that killed 38 Australians.

Mr Poroshenko is in Australia for a two-day visit, with discussions about MH17 top of the agenda.