President Kersti Kaljulaid said she was "embarrassed" by the comments of Mart Helme, 70, who leads the populist far-right party Ekre.

Finnish PM Sanna Marin, 34, is the world's youngest prime minister.

She heads a centre-left coalition with four other parties, all female-led, and has been a rising star for some years.

Mr Helme made his controversial remarks on his party's radio talk-show.

"Now we see how one sales girl has become a prime minister and how some other street activists and non-educated people have also joined the cabinet," he said.

Ms Marin has spoken about growing up in a disadvantaged family. She worked as a sales assistant before going to university and embarking on a political career.

She was the first person in her family to finish high school and attend university.

Responding on Twitter, Ms Marin said she was "extremely proud of Finland".

"Here a child from a poor family can get educated and achieve many things in their lives. The cashier of the shop can become a prime minister," she wrote.

Mart Helme leads the Conservative People's Party of Estonia

Mr Helme said his comments had been misunderstood, but offered an apology to Ms Marin.

He said he had intended to "acknowledge that it is possible to work oneself up from a low social level also into top politics".

"If someone has misunderstood it... then indeed I want to say that I am offering my apology to the prime minister of Finland," he added.

In a statement, Estonia's President Kaljulaid said she had called her Finnish counterpart, Sauli Niinistö, and asked him to convey her apologies to Ms Marin and her government.

"I also admitted to him how embarrassed I am for all this," she said.

Estonian opposition parties called for Mr Helme to resign, or for Prime Minister Jüri Ratas to sack him.

Estonia is the most northerly of the three Baltic states and has linguistic ties with Finland, which lies just across the Gulf of Finland.

Estonian President Kersti Kaljulaid apologised for the minister's remarks

Ekre (The Conservative People's Party of Estonia) entered the coalition government in May after taking 17.8% of the vote in a general election. The party promised to protect an "indigenous Estonia".

Mr Helme has become known for his outspoken statements and controversial behaviour.

When he was sworn in, he - along with his son Martin - made the "OK" hand sign - a symbol that has become an alleged dog-whistle for white nationalists.