In a unanimous declaration, the UN Security Council on Friday demanded "a full, thorough and independent international investigation" into the alleged shooting down of flight MH17 in eastern Ukraine's Donetsk region.

The press statement expressed the council's "deepest sympathies and condolences to the families of the victims, and to the people and governments of all those killed in the crash."

At the start of the emergency council meeting, council members held a moment of silence as a tribute to the 298 victims.

The statement also stressed "the need for all parties to grant immediate access to investigators to the crash site to determine the cause of the incident."

Pro-Russian separatists said earlier Friday that they were allowing experts from the Organization for Security and Cooperation in Europe (OSCE) and from Ukraine's government to enter the crash site.

However, the OSCE said it was denied full access to the site.

"They did not have the freedom of movement that they need to do their job. The crash site is not sealed off," Swiss ambassador to the OSCE, Thomas Greminger, told reporters by phone.

He said a team of 17 monitors had stayed for about 75 minutes and would try again to gain access on Saturday.

"Likely downed" by missile

In a televised press conference in Washington, US President Barack Obama called for an immediate ceasefire in Ukraine and demanded a credible investigation of the downing of the airliner.

Calling the crash an "unspeakable tragedy," Obama said the US has "confidence" that the plane was downed by a surface-to-air missile shot from Russian-backed separatists in Ukraine.

"We don't know exactly what happened," he said, adding that it was still unknown who ordered the shooting.

Obama, who earlier this week ramped up sanctions on Russia over the conflict, called on President Vladimir Putin to "take the path that would result in peace in Ukraine."

Obama said Putin had the most power to mitigate the violence in Ukraine as separatists have received a steady flow of support from Moscow, including anti-aircraft weapons.

The plane was flying at about 33,000 feet (10,000 meters) when it went down, putting it within reach of Russian-made missiles possessed by both Ukrainian and Russian forces.

Speaking at a press conference earlier on Friday in Berlin, Chancellor Angela Merkel called for an immediate halt to the fighting in eastern Ukraine.

"What is important now is for an independent investigation to take place as soon as possible," Merkel said. "For that, a ceasefire is needed, and then it is of course crucial for those responsible to be brought to justice."

Netherlands vows justice

More than half the 298 victims aboard Malaysia Airlines flight MH17 heading from Amsterdam for Kuala Lumpur were Dutch. The loss of 189 compatriots is a loss that has been greatly felt in a country of just 15 million people.

Dutch Prime Minister Mark Rutte called for an independent investigation Friday into Thursday's crash.

"The families have the right to know what happened," he said in a televised press conference from The Hague. "All facts should be laid on the table."

"Let's get one thing extremely clear this afternoon: We will turn over every stone and if it turns out to be an attack, I will not rest until the culprits are brought to justice," Rutte added.

A number of those on board were travelling to attend an international AIDS conference in Melbourne, Australia.

Speaking at a press conference at Amsterdam's Schiphol airport where the plane took off, Malaysia Airlines European Vice President Huib Gorter said the Boeing 777 “had a clean maintenance record,” adding “all systems on the aircraft were running normally” when contact was lost with the aircraft.

"This usual flight route was declared safe by the International Civil Aviation Organization and the crossing was not...subject to restrictions," he added. Gorter said the families of the victims would be given $5,000 for initial expenses.

hc/dr (Reuters, AFP, AP, dpa)