U.S. President Barack Obama announced on Friday that the surface-to-air missile that brought down a Malaysian plane on Thursday was indeed fired from an area of Ukraine controlled by pro-Russian rebels.

Obama also stated that Russian President Vladimir Putin could de-escalate the violent situation in Ukraine by ceasing military support to the Ukrainian separatists, though he has so far refused to do so. 

According to Reuters, Obama's declaration on Friday was the strongest statement yet implying that pro-Russian separatists were responsible for bringing down MH-17.

Obama also stated that Russia is at least partly to blame (if the rebels did indeed shoot down the plane) because they supplied the rebels with the high-tech weaponry necessary to attack a plane flying higher than 10,000 meters. 

Obama asserted that if Putin had "made the decision" to stop the "flow of armaments and fighters" to Ukrainian separatists, then it would stop, reports Reuters. 

"This is a global tragedy," Obama stated, and said a "credible" international investigation must be carried out to determine exactly what happened. The President also declared the shooting down of a commercial airliner by separatist forces an "outrage" of unspeakable proportions. Thus far, it has been established that only one U.S. citizen was on board MH-17 when it crashed. 

OTHER WORLD LEADERS

TONY ABBOTT

President Obama wasn't the only world leader to react to the tragedy. Australian Prime Minister Tony Abbott had only harsh words for Russian officials whose initial response has so far been to lay the blame of MH-17's crash solely on Ukraine.

"I have to tell you that the initial response of the Russian ambassador was to blame Ukraine for this and I have to say that is deeply, deeply unsatisfactory," Abbott said. 

"We all know that there are problems in Ukraine. We also know who is very substantially to blame for those problems, and the idea that Russia can somehow say that none of this has anything to do with them because it happened in Ukrainian airspace frankly does not stand up to any serious scrutiny."

Abbott also said that asking whether Russian President Vladimir Putin would be welcome at this year's G20, given all that may come to light regarding Russia's alleged involvement in the MH-17 tragedy, was "very fair" to ask, though he stopped short of stating Putin would not be welcome. 

BAN KI-MOON

According to the Guardian, United Nations secretary general Ban Ki-Moon expressed his sorrow over the incident and offered his condolences to the families of the victims. He also stated that there is "clearly a need for a full and transparent international investigation." 

Other world leaders echoed Ki-Moon's sentiment and the UN Security Council will convene an emergency congress Friday on the situation in Ukraine. 

MARK RUTTE

Netherlands Prime Minister Mark Rutte also had harsh words for those responsible or anyone who might hinder the investigation into exactly what transpired to bring down MH-17.

"Let me be crystal-clear about this," Rutte told reporters at the Hague, "Should it emerge that it was an attack, I will personally see to it that the perpetrators are brought to justice." 

MH-17 was flying from Amsterdam, in the Netherlands, to Kuala Lumpur, Malaysia when it crashed in eastern Ukraine. 

"We will not rest until they have been brought to book," continued Rutte. "We owe it to the victims and their families."