Ukraine has voiced support for Kremlin critic Alexei Navalny who returned to Russia earlier this month after recovering from a suspected poisoning attempt by Russia's spy agency.

Ukrainian Foreign Minister Dmytro Kuleba said in an interview on local Channel 24: "The enemy of my enemy is my friend.”

"Therefore, if Navalny is the enemy of Putin, then we support Navalny. Everything is very simple,” he added.

Navalny, 44, who received treatment in Germany after alleged poisoning, was arrested in the Russian capital upon his return on Jan. 17. Russian authorities said he had violated probation terms from a suspended sentence on a 2014 money laundering offense, which Navalny says is "politically motivated."

Less than 25 hours after his return, Moscow's Khimki Court ruled that Navalny would remain in custody on 30-day pre-trial detention.

He is now behind bars in Moscow's infamous Matrosskaya Tishina jail.

Relations between Ukraine and Russia have remained fraught since 2014 over the status of Crimea and Donbass regions./aa