He added however that he "has no presidential ambitions" himself.
The former Georgian president was released after a judge turned down the prosecutors' request to place him under house arrest, according to Reuters.
Judge Larysa Tsokol chose to set Saakashvili free.
Ukrainian Prosecutor-General Yuriy Lutsenko later said on ICTV that he will appeal the judge's ruling.
He is charged with "assisting members of criminal organisations and concealing their criminal activity" and could face up to ten years in jail.
Saakashvili has dismissed the charges against him in both countries as trumped up.
A court hearing on the case is expected be held in Kiev on Monday.
The court hearing drew wide media attention both in Georgia and Ukraine, as well as internationally.
But an ugly falling out between the two men saw Saakashvili stripped of his Ukrainian passport - only for him to defy the authorities and force his way back into the conflict-riven country with the help of supporters in September.
When authorities tried to arrest him for the first time on December 5, his supporters freed him from a police van. On December 8, the politician was arrested and placed into a pre-trial detention center in Kiev.
Saakashvili was arrested on allegations that he colluded with Ukrainian businessmen tied to Russian Federation to topple President Petro Poroshenko, something he denies. They also have suggested that Saakashvili's protests are part of a Russian plot against Ukraine.
"Saakashvili has announced an indefinite hunger strike", journalist and close ally Vladimir Fedorin wrote on Facebook, in comments echoed by the former leader's lawyer Ruslan Chornolutskyi to the Interfax-Ukraine news agency.
Inside the courthouse Saakashvili called on his followers to remain calm, saying "we don't want confrontation, we don't want any sharp moves".
"You are jailing your opponents - the way Yanukovych did".
Poroshenko named him the governor of Ukraine's Odesa region in 2015, but Saakashvili resigned the following year, claiming that Poroshenko and other officials were impeding anti-corruption reforms, and became a strong critic of his former patron.