According to Dutch PM Mark Rutte, sending out an international military force to secure the site of the downed Malaysian Airlines jet in eastern Ukraine is “unrealistic”.
The site is currently controlled by pro-Russia rebels who have been accused of shooting down flight MH17.
All 298 people on board – most of them Dutch – died.
In the latest fighting in the area, 13 people were killed as troops try to seize Horlivka from the rebels.
Separately, the US has released images to back its claim of Russian firing into Ukraine.
The images, showing marks on the ground and impact craters, suggest fire from multiple rocket launchers, the US state department says.
The pictures also indicate the separatists are using heavy artillery supplied by Russia, it added.
Russia denies supplying the rebels with heavy weaponry or firing across the frontier with Ukraine.
The rebels have been accused of shooting flight MH17 down by mistake, but Russia blames the Ukrainian military, an allegation Ukraine denies.
The crash site has yet to be properly investigated and some bodies have still not been recovered. An international push is under way to get the site secured.
However, Mark Rutte, speaking to reporters in The Hague, said: “Getting the military upper hand for an international mission in this area is, according to our conclusion, not realistic.”
He said it would be “such a provocation to the separatists that it could destabilize the situation”.
Mark Rutte said all options were being looked at. The Netherlands, Australia and Malaysia had been considering a joint operation.
Dutch experts on Sunday cancelled plans to head to the site after international officials said fighting in the region was still going on.
“We can’t take the risk,” said Alexander Hug, of the Organization for Security and Co-operation in Europe (OSCE).
There are still plans for Australia and the Netherlands to deploy 49 police officers, following a deal struck by Malaysia with the rebels to allow international police at the site.
“Our objective is to get in, get cracking and to get out,” Australian PM Tony Abbott said.
The eastern regions of Donetsk and Luhansk have been gripped by heavy fighting as government forces try to retake rebel strongholds.
Aside from the fighting in Horlivka, shelling was also reported close to the MH17 crash site, near the town of Grabove, on Sunday.
Rebels have prevented journalists going to the site and Ukrainian government forces are said to be nearby.
A total of 227 coffins containing the remains of the victims have been sent for identification to the Netherlands, which is leading the crash investigation.
The first MH17 victim has been identified, though officials did not reveal any details.
Officials say the exact number of bodies already collected will be determined only after forensic experts have completed their examination.
Russia said on Sunday it had set up its own team of experts to investigate the plane crash, according to RIA Novosti agency.