Sydney: Australian Prime Minister Tony Abbott on Saturday welcomed the recovery of more remains from the crash site of Flight MH17 but said it would take at least another week to complete the task.

Some 38 Australian citizens and residents, including children, were among the 298 killed when the Malaysia Airlines plane from Amsterdam to Kuala Lumpur was downed over eastern Ukraine on July 17.

Efforts to collect all the remains have been held up by deadly clashes between government troops and pro-Russian rebels but a Dutch-led police mission was finally able to comb the scattered wreckage yesterday.

"It is good that overnight we`ve had, for the first time, large numbers of Australian and Dutch police on site, large numbers of investigators on site who have been able to begin a thorough, professional search," Abbott said.

"And I can report that more human remains have been recovered; more belongings have been recovered. They will be taken to Kharkiv for repatriation to Holland, eventually repatriation around the world."

Abbott, who has committed hundreds of police, defence and other officials to the task, said while the situation in Ukraine was difficult and dangerous, the importance of the job justified the risk.

"It will be a long and slow process," he told reporters in Sydney, adding he was unable to say how many more bodies had been recovered in addition to the more than 220 coffins already sent back to the Netherlands.

"I expect that our officials will be on site for a week or so yet, that`s assuming nothing goes wrong, because it is a large area that does need to be searched, it is in the order of 50 square kilometres.

"Even if there are no further interruptions, it will take us at least a week to get the job done."

Abbott said the Ukraine government had been cooperating fully, while the Dutch and Australian experts had also had "respectful cooperation from the separatists on site".

"So far at least, people are being as good as their word," Abbott said.

The United States says the pro-Russian insurgents likely shot down the plane with a missile supplied from Russia. But Moscow and the rebels contend the aircraft could have been brought down by a Ukrainian fighter jet.