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Oklahoma City Thunder center Enes Kanter posted a video on social media Saturday, saying he was being held inside a Romanian airport due to passport issues.

Kanter discussed the travel problem, which happened to fall on his birthday, on Twitter:

He later posted a lighthearted photo from the airport with the hashtag "Free Enes:"

An ESPN.com report noted the 25-year-old, who's represented Turkey at the international level, has become an "outspoken critic" of Turkish President Recep Tayyip Erdogan through his support of the Gulen movement.

Kanter's representative said they were "pretty optimistic" they could get Kanter back to the United States because he's in a European Union country, per Brett Dawson of NewsOK.com

The Thunder told ESPN.com they are "working with the league office and gathering information through the appropriate channels."

Oklahoma City's season came to an end April 25 with a Game 5 loss to the Houston Rockets in the first round of the 2017 NBA playoffs.

Kanter averaged 14.3 points and 6.7 rebounds while shooting 54.5 percent from the field across 72 games during his sixth NBA season. He previously played for the Utah Jazz after starting his professional career with Fenerbahce in Turkey.