The Russian government on Friday added the United States and the Czech Republic to its list of "unfriendly" states.

According to Reuters, U.S. diplomatic missions can no longer employ local staff while Czech missions could employ a maximum of 19.

The move comes amid an escalating diplomatic row between Russia and several European countries.

Russian President Vladimir Putin signed a law last month to limit the number of local staff working at foreign diplomatic missions and other agencies. He ordered the government to draw up a list of "unfriendly" states that will be subject to the restrictions.

The government has since formed a list of foreign countries "committing unfriendly actions" toward the Russian Federation, Russian citizens or legal entities. 

These countries will either receive a cap on the number of locally hired employees or be completely banned from employing Russian staff at their diplomatic missions.

Following that announcement, foreign ministry spokeswoman Maria Zakharova said "naturally, the U.S. is on this list."

Russia-U.S. relations have rapidly deteriorated after Joe Biden increased pressure on the Kremlin since becoming U.S. president in January. 

Washington in April announced sanctions and the expulsion of 10 Russian diplomats in retaliation for what it says is interference by the Kremlin in U.S. elections, a massive cyberattack and other hostile activity.

Russia in response expelled 10 U.S. diplomats, banned top U.S. officials from entering the country and prohibited the U.S. embassy from employing foreign nationals.

Tensions have also spiraled with the Czech Republic after Prague accused Russian military intelligence of being behind a deadly explosion at an ammunition depot in the eastern Czech Republic in 2014. 

Moscow said last month it would cap the number of the Czech embassy staff in a tit-for-tat move after the EU country announced it was expelling dozens of Russian diplomats.

(With input from agencies)