In a telephonic conversation, Obama thanked Australian Prime Minister Tony Abbott for his leadership on this issue, including his willingness to send investigators to the crash site as well as federal police if necessary, the White House said in a statement.
"The two leaders agree that a prompt, full, unimpeded and transparent international investigation is an imperative, and they expressed their resolve to push for full, immediate, and secure access for international investigators to the crash site," the statement said.
Obama also called Netherlands Prime Minister Mark Rutte.
"The two leaders reaffirmed their commitment to assure that the crash site is properly secured, that all remains are found and returned home, and that a full, transparent, and unhindered international investigation can proceed," it said.
Instead of de-escalating the situation, they agreed that all evidence indicates Russia is still arming and supplying separatists who continue to engage in deadly acts of aggression against Ukrainian armed forces, the statement said.