WARSAW - Polish Prime Minister Donald Tusk proposed on Thursday that Poland and Russia hold consultations on a joint report on the April 10 crash that killed a Polish president.

Tusk told reporters that the consultations were necessary because the report released Wednesday by the Moscow-based Interstate Aviation Committee (IAC) was incomplete.

The IAC report mainly blames Poland for the disaster, which killed Poland's former President Lech Kaczynski, his wife and 94 political and military VIPs. The Polish delegation was on its way to the commemorations of the 70th anniversary of the Katyn Massacre in which 22,000 Polish officers were executed by the Soviets.

According to the Russian report, the plane's crew had been warned not to land in Smolensk because of bad weather, but they may have decided to do so under pressure from then airforce commander general Andrzej Blasik, who was in the pilots' cabin when the accident occurred.

The Polish side, however, argued that some of the blame lay with flight controllers in Smolensk, who made mistakes in guiding the Polish plane.

Tusk said Thursday that the report presented on Wednesday was incomplete from Poland's point of view. He added that if talks with Russia could not lead to a joint position on the matter, the case could be referred to international institutions.

But the prime minister said that the Smolensk affair did not have to hamper Polish-Russian relations.

Commenting the IAC report, Tusk stressed that Poland was concerned not so much its content as its incompleteness, especially omissions regarding the Russian side's part in the disaster.

He assured that Poland was ready to take its part of the blame but noted that "the other side should also have the courage to show the whole picture."

He added that an official Polish position on the report had been passed to the Russian ambassador in Warsaw.