Tbilisi has asked Kiev to extradite former Georgian president Mikheil Saakashvili, who is locked in a feud with Ukraine's leader, authorities said on Tuesday.

"Ukraine has received a request to search for, detain and extradite Mikheil Saakashvili," Ukraine's deputy justice minister Sergiy Petukhov told reporters.

Citing the Chief Prosecutor's Office of Georgia, Petukhov said that Saakashvili was a defendant in four criminal cases.

The charges include misappropriation of property and abuse of office, among others.

Saakashvili has said the charges are part of a political witch hunt by his opponents. 

Saakashvili, 49, is credited with pushing through pro-Western reforms in his native Georgia which he led from 2004 to 2013. 

In the wake of the pro-Western revolution in Kiev he moved to Ukraine in 2015 to work for the country's authorities as governor of the key Odessa region on the Black Sea.

But he had a major falling out with Poroshenko and accused Kiev of stalling in the fight against corruption.

Ukraine's leader Petro Poroshenko stripped him of his Ukrainian citizenship at the end of July, when the charismatic reformer was out of the country.

He has also been stripped of his Georgian citizenship. 

Saakashvili has pledged to return to Ukraine on September 10 via Poland, and has challenged the authorities to try to stop him. 

Saakashvili rose to power in his Caucasus homeland in a bloodless revolution in 2003 and set about shifting Georgia closer to the West.

That angered Russia, and in 2008 Moscow defeated Georgia in a brief war over a breakaway region.