Australian and Dutch police remain frustrated over a lack of access to the MH17 crash site in eastern Ukraine but Tony Abbott is hopeful.

Australian and Dutch police have been forced to abandon a third attempt to reach the MH17 crash site because of escalating tensions between Ukrainian forces and pro-Russian militia.

However, Prime Minister Tony Abbott is still hopeful they will soon be able to reach the Donetsk area toward Ukraine’s eastern border where the Malaysia Airlines passenger jet was downed on July 17.

The 200 strong unarmed police contingent was on Monday forced to turn around for the second day running due to shelling and gunfire.

Mr Abbott was briefed on Tuesday afternoon about talks to provide a safe corridor for investigators.

“We were optimistic,” the prime minister told Fairfax Radio.

But in the end, investigators didn’t get to set out on Tuesday.

“The team decided not to attempt to travel to the site as fighting had intensified in recent days and had led to the mission being aborted on both previous attempts,” the Australian Federal Police said in a statement.

“The mission will again attempt to enter the crash site when suitable arrangements are in place to provide an appropriately secure area.”

Mr Abbott on Tuesday attended a meeting of the national security committee of cabinet to discuss the “confused situation on the ground”.

He pointed to a commitment by the Ukraine government and pro-Russian separatists fighting on the eastern border to use “their best endeavours” to make the site safe enough for the Dutch-Australian team.

“And it’s high time those commitments were honoured,” Mr Abbott said.

Alexander Hug, the deputy head of a monitoring team from the Organisation for Security and Cooperation in Europe, expressed the his team’s frustration and anger after the second turnaround.

“We are sick and tired of being interrupted by gunfights, despite the fact that we have agreed that there should be a ceasefire,” he said.

Dutch police chief Gerard Bouman believes the chances the police can recover all the remains and evidence is “not very good”.

Mr Abbott spoke with his Malaysian counterpart Najib Razak on Tuesday afternoon and the leaders agreed on their “absolute determination and commitment” to gain access to the site to fulfil a “moral mission” to bring home the bodies of the dead.

The Ukrainian military has seized back a number of villages in the Donetsk region but a spokesman for Ukraine’s national security council has denied Ukrainian forces were fighting within the 20km radius around the crash site in the Donetsk region and blamed the shelling on pro-Russian forces.

Foreign Minister Julie Bishop and Australia’s special envoy Angus Houston have met Ukrainian president Petro Poroshenko to push for an exclusion zone and humanitarian corridor.

Ms Bishop also wants the Ukrainian parliament to this week ratify a deployment agreement she’s signed with her counterpart, Pavlo Klimkin, that would allow Australia to send in armed police or soldiers.

Ukraine and the 11 countries which lost 298 citizens – including up to 39 Australian residents – have also agreed to set up a joint team of prosecutors to examine possible criminal charges against those who downed the plane, which is believed to have been shot down by pro-Russian separatists using a surface-to-air missile launcher.

Europe’s judicial cooperation agency Eurojust will be involved in the process.

Dutch investigators are expected to release an initial report on the plane’s black box recorders this week.

US President Barack Obama and European leaders are considering toughening up sanctions against Russia, particularly in the areas of access to capital markets, defence, dual-use goods and technology.