Ukraine's ex-president Petro Poroshenko returned to Kyiv from Poland on Monday despite the risk of arrest, vowing to help protect the ex-Soviet country from a possible Russian invasion.
Poroshenko, who served as president from 2014 to 2019, was placed under investigation for high treason and left Ukraine in December.
His return comes with Ukraine facing its biggest crisis in years as Russia masses tens of thousands of troops on the border, raising fears of an invasion and prompting warnings from the West.
Poroshenko is a staunch critic of President Volodymyr Zelenskiy, who he accuses of failing to do enough to prevent Russian aggression.
Poroshenko returned to Kyiv early on Monday on a flight from Warsaw and passed through passport control amid chaotic scenes, saying later that border guards had tried to prevent him from entering the country.
After speaking to thousands of supporters who had gathered near the airport, Poroshenko appeared before a court in Kyiv that was to decide whether to place him in pre-trial detention.
He told the crowd at the airport that he had returned to help Ukraine face the "growing threat of Russian invasion" and accused Zelenskiy of "betrayal" of the country.
'Unite and defend Ukraine'
Days of talks between Russia and the West last week have failed to reduce tensions, as Moscow demands wide-ranging concessions including a ban on Ukraine ever joining NATO.
On Friday, Washington accused Moscow of sending saboteurs trained in explosives to stage an incident that could be a pretext to invade the pro-Western neighbor.
Kyiv has also accused Russia of being behind a massive cyberattack on Friday that knocked out key government websites.
"We are here to unite and defend Ukraine," Poroshenko told the crowd, which held up posters reading "We Need Democracy" and "Hands off Poroshenko."
He headed from the airport to the court, where hundreds of supporters chanted his name as he participated in the hearing with two lawyers.
"We are determined to fight today. The truth is with us," he told the crowd during a break in the hearing.
"The authorities are confused, weak, and instead of fighting (Russian President Vladimir) Putin, they are trying to fight us," he said.
One of Ukraine's richest men
Poroshenko, 56, is one of the country's richest men. He was elected president after Russia annexed the peninsula of Crimea and as fighting escalated between Kyiv's troops and Moscow-backed separatists in the industrial east of the country.
In 2019, he was trounced in a presidential election by Zelenskiy, a comedian with no previous political experience.
Poroshenko is now a member of parliament and leader of an opposition party, European Solidarity.
By returning to Ukraine he was following in the footsteps of Georgia's former president Mikheil Saakashvili and Putin's top critic Alexei Navalny who both returned to their countries in defiance of the authorities and are now in jail.
Navalny returned to Russia on the same day a year ago.
Authorities say they are investigating dozens of alleged crimes in which Poroshenko might be involved.
Among the allegations is that he aided the self-proclaimed Donetsk and Lugansk People's Republics in selling around 1.5 billion hryvnia ($54 million) worth of coal to Kyiv between 2014 and 2015.
Prosecutors have accused Poroshenko of working on the scheme with pro-Kremlin lawmaker Viktor Medvedchuk, a friend of Putin's who is also facing treason and terrorism charges.
Poroshenko faces up to 15 years in prison if convicted in the treason case.
He has denied any wrongdoing and accused Zelenskiy, 43, of orchestrating the charges in order to deflect attention from his domestic and foreign policy failures.
Ukraine has been fighting pro-Russian separatists in the eastern Donetsk and Lugansk regions since 2014, in a conflict that has claimed more than 13,000 lives.
Poroshenko, often called Ukraine's "chocolate king," owns a confectionery empire and two television channels. Forbes magazine estimates his fortune to be worth $1.6 billion.