A Romanian court has expelled and banned a pro-Russian Serbian nationalist for 15 years after he showed an interest in obtaining classified information on Romanian military installations.

Romania's Intelligence Service said Tuesday that Bratislav Zivkovic, 42, is a commander of Serbia's Chetnik paramilitary and went to Crimea in 2014-15 to support Russia's annexation there.

It said Zivkovic wanted to obtain classified Romanian documents on critical infrastructure and national and allied military objectives in southeast Romania "with the intention of affecting our strategic partnerships."

The agency said he hadn't accessed any classified information, but posed a risk to Romania's national security. Romania is a member of NATO but Serbia, a staunch Russian ally, is not.

The Bucharest Appeal Court ruled him "undesirable" Tuesday, ordering him expelled.