KYIV, May 10 (Reuters) - Leonid Kravchuk, a former communist who helped sign the Soviet Union's death warrant and then served as the first president of independent Ukraine, died on Tuesday at the age of 88.

Volodymyr Zelenskiy, now leading Ukraine as it confronts invading Russian forces, described Kravchuk as a wise leader who guided the country in the chaotic first years of independence from Soviet rule.

"He was a person always able to find wise words and express them in such a way that they were heard by all Ukrainians," Zelenskiy said in his nightly video address.

"Particularly in times of crisis. When the future of an entire country can depend on the wisdom of one person."

Kravchuk, the president said, displayed such wisdom as Ukraine's national movement gained strength in the late 1980s, culminating in a December 1991 referendum in which more than 90% of voters chose independence.

Kravchuk was elected president the same day.

"He acted brilliantly in 1991 and it is only now that appears that things were easy for him," Zelenskiy said.

Kravchuk became known as the "wily fox" as he rose through the ranks of Ukraine's Communist Party, taking over as head of parliament in what was then a Soviet republic in 1990.

But he quit the party soon after a failed coup coup against Soviet leader Mikhail Gorbachev in August 1991. Ukraine's parliament adopted a declaration of independence the same month.

In December 1991, he signed the Belovezha accords with Russian President Boris Yeltsin and Belarusian leader Stanislav Shushkevich, which effectively triggered the Soviet Union's collapse.

Yeltsin died in 2007 while Shushkevich died last week.