Estonian President Kersti Kaljulaid called her Finnish counterpart Sauli Niinistö on Monday to formally apologise for comments made a day earlier by Estonian Interior Minister Mart Helme.
Helme, who leads the right-wing populist Conservative People's Party (Ekre), criticised Finland's new government and Prime Minister Sanna Marin in a radio interview.
Niinistö's office issued a statement saying that he had passed Kaljulaid's apology on to Marin and her cabinet.
"A salesgirl has become PM"
In an interview with commercial radio channel TRE, Helme said, "Now we can see that a salesgirl has become prime minister and some other street activist and uneducated person has also become a member of the government."
He linked the new government to the Finnish Civil War of 1918.
"Now we can actually see to some extent the historical revenge of the Reds on the Whites, that is to say, the Reds who wanted to liquidate the Finnish state during the Civil War have now come to power and are now desperately trying to liquidate Finland, making it a Euro-province," he said.
Besides Marin's SDP, the five-party coalition includes the Centre Party, the Greens, the Left Alliance and the Swedish People's Party.
Helme predicted that opposition Finns Party chair Jussi Halla-aho would become Finland's next Finnish prime minister because "something as unintelligible as what is happening in Finland has probably not happened there for centuries". The Finns Party and Ekre are both part of the far-right Identity and Democracy group in the European Parliament.
Marin responds indirectly
On Sunday the Director of Government Communications in the Prime Minister's Office, Päivi Anttikoski, said that Marin had "no reason" to respond to the comments.
Later on Sunday, Marin replied indirectly with a tweet saying, "I'm extremely proud of Finland. Here the child of a poor family can educate themselves highly and reach many goals in life. A cashier can become Prime Minister, for instance. Finland would not survive without its workers. I highly value the work of every employee, professional and entrepreneur!"
Estonian Prime Minister Jüri Ratas called for "respectful" cooperation with "friend and ally" Finland, saying it "has nothing to do with the composition of a government coalition or the parties that lead it".
Foreign minister Urmas Reinsalu called the comments "inappropriate", while a range of other politicians also decried the statements.
According to Estonian public broadcaster ERR, two of the country's opposition parties say they will seek a vote of no confidence in the government if Ratas does not force Helme out.