The Amsterdam-to-Kuala Lumpur Flight MH17 was shot down on July 17, 2014, by a missile, killing all 298 people aboard.
On this day in the Netherlands will open the memorial to the victims of flight MH17. The global criminal probe has concluded that the missile was sacked from rebel-controlled territory by a mobile launcher trucked in from Russian Federation.
The initiators of the opening of the memorial place called it "a living memorial" - altogether 298 trees were planted, according to the number of people killed in the disaster.
Monday afternoon's commemoration comes as global investigators continue their painstaking probe aimed at bringing to justice those responsible for shooting down Flight 17 and killing all 298 passengers and crew.
Poroshenko said that he was "convinced that the objectivity and impartiality of Dutch justice will complete this path".
"We are also pleased to note that the Dutch Public Prosecution Service will make the necessary decisions concerning prosecution at the appropriate time given the criminal investigation is still ongoing".
Nations involved in the probe have agreed to prosecute any suspects in the Netherlands, home to almost 200 of the victims.More news: Credit Card-Checking Porn Site Age Gates are Nearly Here
U.S. State Department spokeswoman Heather Nauert said that Washington "urges other states to cooperate fully in order to ensure those responsible are brought to justice".
The victims' names has been engraved on a statue in the shape of an eye pointed skywards.
The O'Briens know it may take years for the investigative and prosecution process to play out, but the 298 people whose names were read out by relatives at Monday's ceremony had "lost the chance to live, so the truth matters". In the silence preceding the commemoration planes could be seen and heard flying to and from the airport.
In Malaysia, Dato Sri Liow Tiong, the transport minister, promised justice for the victims.
"We will not rest until all the facts are known and justice is served", he said.
Nataliya Vasilyeva in Moscow and Eileen Ng in Kuala Lumpur contributed.