MOSCOW/PRAGUE • The Czech Republic on Thursday ordered Russia to remove most of its remaining diplomatic staff from Prague in an escalation of the worst dispute between the two nations in decades.

The spy row flared last Saturday when Prague expelled 18 Russian staff, whom it identified as intelligence officers.

It said two Russian spies accused of a nerve agent poisoning in Britain in 2018 were also behind a 2014 explosion at a Czech ammunition depot that killed two people.

Russia denied the Czech accusations and on Sunday ordered out 20 Czech staff in retaliation.

Thursday's decision, announced by Foreign Minister Jakub Kulhanek, requires Russia to have the same number of diplomatic staff as the Czech Republic has in Moscow.

That means Russia will have to withdraw 63 diplomats and other staff from Prague, although Prague gave it until the end of next month to do so.

Together with the initial step, this will greatly reduce the biggest foreign mission to Prague that is much larger than the Czech mission in Moscow.

"We will put a ceiling on the number of diplomats at the Russian embassy in Prague at the current level of our embassy in Moscow," Mr Kulhanek said.

"I do not want to needlessly escalate... but the Czech Republic is a self-confident country and will act as such. This is not aimed against Russians or the Russian nation, but a reaction to activities of Russian secret services on our territory."

Russia's Foreign Ministry reacted, demanding a reduction in the Czech embassy's staffing level, alluding to disparity in numbers of local employees. "The (Czech) ambassador was told that we reserve the right to take other steps in the event the hysterical anti-Russian campaign spirals further," Russian Foreign Ministry spokesman Maria Zakharova said in a statement.

At a time of acute tension in Russia's relations with the West, the dispute has prompted Nato and the European Union to throw their support behind the Czech Republic, which is a member of both blocs.

"Allies express deep concern over the destabilising actions Russia continues to carry out across the Euro-Atlantic area, including on alliance territory, and stand in full solidarity with the Czech Republic," Nato's 30 allies said in a statement.

Slovakia expelled three Russian envoys on Thursday in solidarity with the Czech Republic. The Russian response to that step was not immediately clear.

In the last week, Moscow has also kicked out diplomats from Bulgaria, Poland and the United States in retaliation for expulsions of its own staff.

Kremlin spokesman Dmitry Peskov said Moscow took a negative view of Prague's "hysteria". In a speech on Wednesday, President Vladimir Putin warned foreign powers not to cross Russia's "red lines", saying Moscow would make them regret it.

The Russian embassy's size in Prague is an overhang from the pre-1989 communist era.

REUTERS