Cockpit recorders from a plane crash which killed the president of Poland and 95 other people in April, show on-board systems gave at least a dozen warnings to regain altitude in the minute before the crash.
Transcripts show the warning system told the pilots numerous times to pull up because there was terrain ahead.
It is not clear from the transcripts why the pilots only tried to pull higher when it was already too late.
The last sound recorded was a prolonged curse by an unidentified person in the cockpit.
President Lech Kaczynski and his entourage were going to a ceremony in the Katyn forest on 10 April marking the 70th anniversary of the murder of some 22,000 Polish army officers and civilians there by the Soviet NKVD secret police.
Copies of the cockpit recordings were given to Polish Interior Minister Jerzy Miller by Russia on Monday.
The government decided to publish the transcripts to quell speculation about the reasons for the crash. Earlier this month, aviation officials in Moscow said there were non-crew members in the cockpit just before the crash.
