Estonia said Monday it would expel the Russian ambassador from Tallinn in retaliation for Moscow's expulsion of the Estonian ambassador.
"We stand by the principle of parity in relations with Russia," the Estonian ministry of foreign affairs said in a tweet, adding that the Russian ambassador would have to leave at the same time as his Estonian counterpart, ordered by Moscow to leave on February 7.
Russia has lowered its diplomatic representation in Estonia to charge d'affaires and asked the Estonian ambassador to leave Russia, the Russian foreign ministry said on Monday.
Estonia has pledged to send all its 155-mm howitzers to Ukraine.
(With input from AFP)