Pro-Russian separatists in eastern Ukraine are to give international investigators access to the crash site of a Malaysia Airlines jet.
The rebels vowed to secure the site and allow the recovery of bodies, the Organization for the Security and Co-operation in Europe said.
The plane, carrying 298 people, crashed in rebel-held territory on Thursday.
The two sides in Ukraine's civil conflict have accused each other of shooting the jet down with a missile.
The Boeing 777 was flying from Amsterdam to Kuala Lumpur. It fell between Krasni Luch in Luhansk region and Shakhtarsk in the neighbouring region of Donetsk.
Latest figures released by Malaysia Airlines show the plane was carrying at least 173 Dutch nationals, 27 Australians, 44 Malaysians (including 15 crew), 12 Indonesians and nine Britons.
The plane came down near the village of Grabovo in Ukraine on Thursday
Debris from the plane covers a very large area
This photo shows a broken watch found on a plastic cover near the site
Ukrainian coal miners are seen searching a sunflower field close to the crash site
Other passengers came from Germany, Belgium, the Philippines and Canada. The dead include world-renowned Dutch researcher Joep Lange who was among a number of passengers en route to an international Aids conference in Australia.
It is the second disaster suffered by Malaysia Airlines this year. Flight MH370 disappeared en route from Malaysia to China in March and has still not been found.
'Catastrophe'
The separatists pledged to provide assistance after holding a video conference with senior representatives from the OSCE, Ukraine and Russia.
In a statement, the OSCE said the rebels had agreed to "close off the site of the catastrophe and allow local authorities to start preparations for the recovery of bodies".
They would also guarantee "safe access" to international investigators and OSCE monitors and co-operate with Ukrainian authorities.
The OSCE said 30 members of its Ukrainian monitoring mission were expected to arrive at the plane crash site later on Friday.
Ukraine has declared the area a no-fly zone, while other airlines have announced they are now setting flight paths to avoid eastern Ukraine.
Rescue workers said on Friday they had recovered one of the plane's black box flight recorders after searching through debris spread across several kilometres.
The Interfax-Ukraine news agency earlier reported that another black box was found by separatist fighters and handed over to Moscow. Observers say the move, if confirmed, is likely to cause international controversy.
US and Ukrainian officials said they believed the plane had been brought down by a missile - a Buk thought to have been used by the rebels in Ukraine before.
But Ukraine's defence ministry said there were no Air Force jets in the area and no surface-to-air systems being used against the rebels.
Earlier on Thursday, Ukrainian officials blamed the Russian Air Force for shooting down one of its ground attack jets on Wednesday, and a transport plane on Monday.
International leaders, including US President Barack Obama and German Chancellor Angela Merkel, have called for an immediate ceasefire in eastern Ukraine.
Shelling is continuing as Ukrainian forces try to advance against the rebels.
The UN Security Council is to hold an emergency meeting on the plane disaster on Friday morning in New York.
Cr. BBC news and CNN news