NATO is downsizing the Russian delegation to the U.S.-led defense alliance, cutting the maximum staff allowed to 30.

NATO deputy spokeswoman Carmen Romero said Friday the new ceiling on personnel from NATO partner countries applies to all 41 nations concerned.

However, Russia is believed to be the only nation whose delegation, now around 50, tops that limit.

Romero said the new staff limits, to go into effect over the next nine months, are a "practical measure" not aimed at Russia, whose relations with NATO have deteriorated since the Kremlin's 2014 annexation of Crimea. She said Russia's ambassador and three other delegation members will continue to enjoy unescorted access to NATO premises.

In 2009, NATO expelled two Russian diplomats from its Brussels headquarters over accusations of espionage.