MOSCOW (Reuters) - President Boris Yeltsin said in his state of the nation address on Tuesday that the government would be changed if it failed to resolve strategic economic tasks. "If the government is not able to solve these strategic tasks, then we will have another government," he told a joint session of both houses of parliament. Yeltsin recently indicated he wanted to keep liberals Anatoly Chubais and Boris Nemtsov, both first deputy prime ministers, until the end of his four-year term in the year 2000. But the government is due to report to Yeltsin on February 26 on its record during 1997 and the 67-year-old president has made clear he is looking for proof that Russia is finally on the path to strong economic growth after years of steep declines. After last year's state of the nation address he carried out a radical cabinet reshuffle, drafting Chubais and Nemtsov into the government to help kickstart stalled market reforms. Any cabinet changes now would be pounced on for clues to the question of who will succeed Yeltsin in 2000. Yeltsin himself has said he will not seek re-election, though he may still change his mind. Possible successors include Prime Minister Viktor Chernomyrdin, the telegenic Nemtsov, Moscow mayor Yuri Luzhkov and law-and-order reserve general Alexander Lebed.