President Barack Obama spoke about the downed plane in eastern Ukraine from the White House Monday morning. He called for international investigators to have "immediate and full access" to the site where a passenger jet was shot down last week.
U.S. officials have been seeking to build a case that the plane was shot down by pro-Russian separatists.
U.S. officials said that it's unlikely the separatists could have fired a missile without assistance from Russia. Obama accused pro-Russian separatists in the area of removing evidence and bodies from the crash site, and said it raises the question of what the separatists might be trying to hide.
The president said the burden is on Russia and President Vladimir Putin to compel the separatists to cooperate with the investigation. Obama said that if Russia continues to violate Ukraine's sovereignty, Moscow "will only further isolate itself" and the economic costs will continue to increase.
Four days after the plane was shot down, international investigators have still had only limited access to the crash site. They're being hindered by the pro-Russia fighters who control the territory. Emergency workers removed 21 more bodies on Monday. Dutch investigators are demanding that the refrigerated train cars in which bodies are being stored be allowed to leave as soon as possible.
The Malaysia Airlines plane was brought down Thursday with nearly 300 people on board. The White House has been calling for an international investigation into the crash and a cease-fire around the area.
This report includes information from The Associated Press.