Ukraine's President Petro Poroshenko announced his country is preparing international requests that the Donetsk and Luhansk "republics" be considered as terrorist organizations.

His words come after a Malaysia Airlines Boeing 777 crashed in eastern Ukraine, where pro-Russian rebels have held towns and cities under their control since early this spring.

All 298 passengers are confirmed dead, with 192 of the victims coming from the Netherlands.

The list issued Saturday by Malaysia's government also included 43 Malaysians (including 15 crew), 27 Australians, 12 Indonesians and 10 Britons (one of them with dual South African nationality), 4 Germans, 4 Belgians, three from the Philippines, and one each from Canada and New Zealand.

Some reports, including by US intelligence officials, suggest a missile of unknown origin was shot at the plane.

Ukraine immediately claimed that rebels were behind the incident, while Russian President Vladimir Putin pointed a finger at Kiev saying the country was responsible for the unrest in its east.

Rebels themselves argue Ukraine could have downed the aircraft.

Dutch Foreign Minister Frans Timmermans traveled to Ukraine to discuss the international investigation that is to be held to find out the reasons for the crash.

After informing Timmermans of an attempt to foil an ongoing probe carried out by Organization for Security and Cooperation in Europe (OSCE) observers at the site of the crash, Poroshenko assured him Ukraine would not "tolerate" any interference in the investigation.

He reiterated his country's stance that the self-proclaimed "Donetsk People's Republic" and "Luhansk People's Republic" and their leaderships were involved in the incident.

"I am convinced that terrorist should be necessarily tried," Russia's ITAR-TASS agency quoted him as saying.

EU and US officials are seeking to pressure Moscow into securing unhindered access to the place where the Boeing 777 crashed.

They urge Russia to exert its influence on the Donbass rebels so that those in charge can explore the site untroubled.

Kiev officials, for their part, accuse pro-Russian militiamen, which were reported to restrict monitors' movement around the area, of attempting to destroy evidence of an "international crime".