Bereaved relatives attend a memorial service at the National Monument near Amsterdam for the 298 people killed four years ago when flight MH17 was shot down over war-torn Ukraine

Bereaved relatives Tuesday held a solemn ceremony to remember flight MH17, as the families of those lost when the plane was shot down over war-torn Ukraine four years ago await justice.

All 298 people on the Malaysia Airlines flight en route from Amsterdam to Kuala Lumpur were killed when a Russian-made Buk missile slammed into the plane over territory held by pro-Russian rebels in eastern Ukraine on July 17, 2014.

The ceremony was organised by the victims' families at a memorial opened last year near Schiphol airport, close to Amsterdam.

Prime Minister Mark Rutte led a procession of relatives and friends in laying flowers at the memorial, planted with 298 trees in the shape of a green ribbon.

The names of each of the victims, who were mostly Dutch but included many other nationalities including Australians and Malaysians, were read aloud.

President of the victims association, Piet Ploeg, highlighted the difficult situation the families find themselves in.

"We are confronted by constant delays and foot-dragging, with some remains still in Ukraine, and we have still yet to identify the remains of all our loved ones," he said.

Ploeg's 58-year-old brother, Alex, who died alongside his wife Edith and 18-year-old son Robert, is one of only two victims who has not yet been identified.

In May, Dutch-led international investigators concluded that the BUK missile which blew up the plane had come from a Russian military brigade based in southwestern Kursk, and travelled in a convoy into eastern Ukraine.

That information pushed the Netherlands, backed by Australia, to publicly say for the first time that they held Moscow responsible for the disaster. The two nations are considering whether to launch a case in the international courts against Russia.

-- 'Black page in history' --

While investigators have called for information on two possible suspects, no charges have yet been brought and no-one has appeared in the high-security court in Schiphol where any trial will be held.

"A black page in history that will be remembered around the world today. The Netherlands will continue to fight for truth and justice," vowed Dutch Foreign Minister Stef Blok in a tweet.

G7 nations at the weekend urged Russia to "account for its role" in the 2014 disaster, saying the joint investigation had yielded "compelling, significant and deeply disturbing" findings on Russia's involvement.

"We are united in our support of Australia and the Netherlands as they call on Russia to account for its role in this incident," the statement said.

Russia has repeatedly denied any role in the crash, and instead blamed Ukraine.

But in June families organised a powerful protest, arranging 298 empty white chairs on grounds outside the Russian embassy in The Hague in a silent rebuke to the officials inside.