Ukrainian pilot Nadiya Savchenko, who spent two years in Russian custody before she was released last week, was sworn in as a lawmaker in the national parliament on Tuesday.
Savchenko was elected a lawmaker in 2014 while she was in custody. She told fellow lawmakers in the Rada, the parliament in Kiev, that she would it make her priority to fight for the release of other Ukrainians held in Russia. Ukraine describes them as political prisoners.
"You absolutely have to pull out every single prisoner," the 35-year old said before singing the national anthem.
Savchenko had resigned from the army and was serving in a volunteer Ukrainian battalion in eastern Ukraine when she was captured by Russia-backed separatists in June 2014.
She was put on trial and convicted in March of involvement in the killing of two Russian journalists in eastern Ukraine, a charge that she has rejected.
Savchenko returned to Ukraine last week to a hero's welcome after she was pardoned by Russian President Vladimir Putin as part of a prisoner swap.
At the end of her speech, Savchenko took down a poster with her picture from the rostrum, where it has been for months. She replaced it with one depicting several other people and calling for the release of "prisoners of the Kremlin."
Savchenko is a member of former Prime Minister Yulia Tymoshenko's party, which in February left Ukraine's governing coalition.
Her popularity could help her become an influential lawmaker and she has said she would be willing serve her country in any capacity — including that of president.