(Adds demand for humanitarian corridor)
MOSCOW, July 18 Ukrainian President Petro Poroshenko informed German Chancellor Angela Merkel and British Prime Minister David Cameron on Friday about the international team investigating the circumstances of Malaysian airliner tragedy, his press service said.
"The president stressed that the black boxes from the aircraft should remain with international experts and not be passed to a third country by terrorists," his press service said in a statement.
"He invited German and British experts to get involved in the work."
In a separate conversation with Australian Prime Minister Tony Abbott, Poroshenko said a humanitarian corridor needed to be created in the east, where pro-Russian separatists are fighting government forces, to help evacuate the bodies of those killed when the airliner was downed. (Reporting by Natalia Zinets, writing by Elizabeth Piper, Editing by Alissa de Carbonnel and Kevin Liffey)