"We don't know the causes of this tragedy today, but we know that we are related to it," Defense Minister Oleksandr Kuzmuk said at a news conference.
Air defense chief Gen. Volodymyr Tkachov said it was possible the airliner was unintentionally shot down by a missile fired by Ukrainian forces during military exercises, as Russian and U.S. officials have alleged. However, he stopped short of confirming that explanation outright.
Ukrainian President Leonid Kuchma had not yet accepted the resignations Saturday.
The statements Saturday were the clearest admission of Ukrainian responsibility since the Sibir Airlines Tu-154 airliner went down Oct. 4 off the Black Sea coast, near the Russian city of Sochi. Most of the passengers were recent Russian immigrants to Israel.
"I bring my apologies to victims' relatives and close ones, I bring my apologies to Ukraine's president, the government, parliament and the Ukrainian people," Kuzmuk said.
Kuchma reiterated on Saturday that he will accept the conclusions of expert investigators, regardless of their content.
"Ukraine will be ready to do everything necessary to soften the pain and suffering of the victims' families," he said in a written statement.
"We tried to be as transparent as possible from the very beginning and have taken all steps to ensure an efficient probe and to present information in full," he said, adding that a new state commission is reviewing Ukrainian air defenses to prevent similar accidents.
Hours after the crash, U.S. officials said that the tragedy had been caused by an S-200 missile fired by Ukraine during military exercises on the Crimean Peninsula.
Vladimir Rushailo, the chief of the Russian commission investigating the crash, said in the Black Sea city of Sochi that he was convinced the aircraft had been hit by an anti-aircraft missile.
Rushailo said Saturday the missile was believed to have exploded 50 feet above the airliner, blasting it with shrapnel. The plane's captain and navigator were killed instantly, he said.
Rushailo said investigators found 350 holes in fragments of the aircraft recovered from the Black Sea. On Saturday, Ukrainian officials conceded there was strong evidence of a missile strike.
"On the basis of the preliminary conclusions of the experts, the cause of the air crash could have been the unintended destruction of the plane by a missile during exercises," Tkachov said.
Russian investigators had initially focused on the possibility of a terror attack, but later signaled that they were considering the missile theory more likely, especially after discovering metal balls similar to shrapnel contained in the missile's warhead in victims' bodies and in the body of the plane.
Tkachov said he was prepared to "take responsibility both morally nd legally."
Kuzmuk, the defense minister, is popular in Ukraine but has been under some pressure to resign ever since an accident in April 2000 in which a defective missile fired during exercises slammed into an apartment building near Kiev, killing three people.
By MARINA SYSOEVA
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