Moldova says it will expel 45 Russian diplomats and other embassy staff because of their “unfriendly actions”.

The total will be cut to just 25 – a figure closer to the number Moldova has at its Moscow embassy.

Since Russia’s full-scale invasion of Ukraine in February 2022 the Moldovan government has accused Moscow of spying and backing opposition groups.

Russia condemned the expulsion and said it would “not go unanswered”.

On Tuesday, Moldova’s foreign ministry voiced concern about a media report on new surveillance equipment installed on the Russian embassy roof and a neighbouring building used by Russia. The report came from Russian investigative media site Insider and Moldova’s Jurnal TV channel.

Announcing the expulsion on Wednesday, the ministry said it was prompted by “ongoing tensions and unfriendly actions” and the Russians would have to leave by 15 August.

“For many years we have been the object of hostile Russian actions and policies. Many of them were made through the embassy,” said Moldovan Foreign Minister Nicu Popescu.

Russian foreign ministry spokeswoman Maria Zakharova said Moldova’s “unfriendly step will not go unanswered”. She said it would mean restrictions on consular services and on Moldovans’ contacts with Russia, though she did not announce specific measures.

With a population of just 2.6 million, Moldova is one of Europe’s poorest economies and has been heavily exposed to the war in neighbouring Ukraine.

It has faced a major energy crisis because its power infrastructure dates back to the Soviet era. Not only did Russia restrict its gas supplies but its attacks on Ukraine’s power grid also caused sporadic power cuts in Moldova. The invasion also triggered an influx of Ukrainian refugees, putting a strain on Moldova’s public services.

Russia backs separatists controlling a breakaway territory in Moldova – Transnistria – in a frozen conflict that has festered since the 1990s.