The father of three children killed in the 2014 downing of flight MH17 over Ukraine slammed President Donald Trump for failing to hold Russia accountable for the crash.

International investigators determined the missile that attacked the plane belonged to Russian forces, but Russia has denied responsibility.

Trump declined to hold Russia accountable for anything specific when asked during his joint press conference with Russian President Vladimir Putin on Monday.

A father who lost three of his children in the 2014 downing of flight MH17 over Ukraine publicly slammed President Donald Trump for failing to hold Russian President Vladimir Putin accountable for the attack during their joint summit and press conference on Monday.

Malaysia Airlines flight 17, a scheduled passenger flight from Amsterdam to Kuala Lumpur, was shot down by a missile over the Ukraine-Russia border in July 2014, killing all 283 passengers and 15 crew members on board. The crash took place in the context of the war in Donbas, fought between Ukrainian forces and pro-Russian separatists.

After the deadly crash, international investigators from the Netherlands and Australia definitively concluded that both the missile that attacked the plane as well as the tanks that transported the missile belonged to the Russian military. The site of the downing was in an area controlled by pro-Russian forces, but Moscow has consistently denied any involvement with the incident.

In a Facebook post, Anthony Maslin of Perth, Australia criticized Trump for not taking the opportunity to publicly hold Putin responsible for the downing on the fourth anniversary of the crash.

When asked by a reporter if he held Russia accountable for anything in particular during his joint press conference with Putin, Trump dodged, saying both Russia and the US were accountable and both countries had been "foolish" in general about their relations.

"Mr Trump, you invented and speak a lot about 'fake news.' But lets try talking about something thats not fake… lets call them irrefutable facts," Maslin wrote in the post, which included a photo of his children Evie, Mo, and Otis who were then 10, 12, and 8, respectively, when they passed away in the crash.

"That passenger flight MH17 was shot out of the sky and 298 innocent people were murdered is an irrefutable fact. That the plane was hit by a Russian missile has been proven to be an irrefutable fact. That this killed our 3 beautiful children and their grandfather, and destroyed our life and many other lives in the process, is an irrefutable fact," he continued.

Maslin and his wife, Marite Norris, have since welcomed a baby girl, Violet, in May 2016 after the tragic loss of their young children.

"It's not anger that I feel towards the two of you, its something much, much worse," he said of Trump and Putin. "It's pity. You have no empathy for your fellow man, and you clearly have no idea what love is. So you have nothing."