VILNIUS, June 17 (Reuters) - Estonian Prime Minister Kaja Kallas is tipped become the European Union's next foreign policy boss, but her tough stance on Russia may raise doubts whether she can represent views from across the bloc.

EU leaders' informal talkson Monday, their first since European Parliament election, focus on the appointments for the bloc's top jobs with European Commission Ursula von der Leyen expected to secure a second term and EU diplomats say Kallas is in line for the foreign affairs role.

Kallas, who turns 47 on Tuesday, has made her name as an eloquent critic of neighbouring Russia and its expansionist aims since she became Estonian prime minister in early 2021.

An uncompromising voice in the EU and NATO for unconditional support to Kyiv and for containing Moscow, she led her country of 1.4 million people to become among the highest per-capita military donors to Ukraine.

Kallas is wanted in Russia since February, for her role in removing Soviet-era monuments in her country.

Born in Tallinn, she is the great-granddaughter of the first Estonian chief of police as the newly independent country emerged from the Russian Empire after the First World War only to be absorbed into Soviet Union in 1940.

Kallas' mother was only six months old when her family was forcibly relocated to Siberia in 1949 along with 20,000 other Estonians.

"Russia hasn't changed," she said last year on marking an anniversary of her mother's exile. "This evil lives on in Russia."

Unassuming and open, Kallas is well regarded abroad, though not all of bloc's countries share her dogged defiance of Russia. Above all, Hungary's Viktor Orban has maintained friendly ties with Moscow even after its invasion of Ukraine.

However, her popularity at home suffered when local media revealed last year that her husband was involved in a business which continued its operations in Russia even as Kallas publicly criticised all who did so.

Her government also raised taxes shortly after the 2023 elections and legalised same-sex marriage, which almost half of the country opposes.

Kallas' is a second-generation politician.

Her father was the governor of the newly independent Estonia's central bank, established the liberal Reform Party in 1994, which he led for a decade, and served as Estonia's prime minister and later vice president of the European Commission led by Jose Manuel Barroso.

In 2011, Kaja Kallas left a career as a partner at a major Tallin law firm to run, successfully, for the Estonian and then European parliaments on a Reform party ticket. After leading the Reform Party since 2018 she became Estonia's first female prime minister in 2021.

Kallas, known for her uncompromising drive in pushing through policies, has been accused of arrogance by some of her detractors.

Kallas has no doubt her small country's security depends on Brussels.

"If Europe is united and strong, Estonia will also be strong," she told the Estonian parliament in 2022. (Reporting by Andrius Sytas in Vilnius; editing by Niklas Pollard and Tomasz Janowski)