The government has warned that citizens who depart for Ukraine as a volunteer soldier without state approval can face up to a year in prison.

The foreign ministry on Monday said that entering Ukraine, currently under a travel ban amid the Russian invasion, is a violation of the passport law. Punishment also includes a fine of up to ten million won or passport annulment.

The ministry urged the public to refrain from making unauthorized visits to Ukraine.

This reiteration by the government regarding the travel ban comes as a former Navy special warfare officer Rhee Keun on Sunday said that he left for Ukraine via a clandestine route. Rising to fame through a popular YouTube channel, Rhee stated that he could not sit idly by knowing he had the capacity to help the Ukrainians.

A ministry official said Rhee and a number of others are believed to have left for Ukraine, but that their exact locations cannot be disclosed due to privacy issues.