An international military mission to secure the MH17 crash site in rebel-held Ukraine is currently "unrealistic," Dutch Prime Minister Mark Rutte said on Sunday.

"Getting the military upper hand for an international mission in this area is, according to our conclusion, not realistic," Rutte told journalists in The Hague, pointing to the presence of heavily armed separatists and the proximity of the Russian border.

"Not even if we choose for a massive military commitment, even then getting the military upper hand is not realistic," Rutte said amid discussions about how to secure the site so remaining bodies can be removed and crash investigators get to work.

Rutte said that "all options" were being looked at for securing the site, and that the security situation was being assessed on a daily basis.

Heavy shelling around the crash site of Malaysian flight MH17 on Sunday forced Dutch and Australian police to scrap a planned examination of the scene.

The unarmed contingent of law enforcers was due at the location 10 days after the disaster, following a deal with rebels that sought to enable a long-delayed probe.

But international observers overseeing the trip abruptly cancelled the plans after clashes shattered a supposed truce between government forces and insurgents in the area around the site, where some remains of the 298 victims still lie decomposing under the summer sun.

Over 200 bodies have been sent to the Netherlands for identification. The Netherlands lost 193 citizens on the flight, and is in charge of the crash investigation.

"We concluded with our international partners that there's a real risk of such an international military mission becoming directly involved in the conflict in Ukraine," Rutte said.

The conflict "would then acquire an international dimension that would lead to further escalation," added the premier.

"So the success of the repatriation mission depends on preventing an escalation in this area. The less potential the mission has for escalation, the more quickly we will be able to complete our task," he said.

Australian Prime Minister Tony Abbott had earlier announced that 49 officers from the Netherlands and Australia -- which together lost some 221 citizens in the crash -- were due at the scene Sunday and that there would be "considerably more on site in coming days".

That came after Malaysian Prime Minister Najib Razak said he had reached an agreement with the pro-Russian insurgents controlling the site to allow a police deployment.

Following the postponement, Rutte said Dutch Foreign Minister Frans Timmermans and his Australian counterpart Julie Bishop will travel to Kiev later on Sunday to get the Ukrainian parliament to approve the deployment of a broadened police mission to secure the site.

"The cabinet decided today to strengthen our capacity (in Ukraine) step-by-step," Rutte said.