The slain woman was later identified as 21-year-old Hannah Bladon, a University of Birmingham student who was taking part in an exchange program with Hebrew University.
The incident occurred on the light rail network near Jerusalem's municipality building and the walled Old City.
Stern began to treat the woman but she "lost consciousness. due to the seriousness of her wounds".
"She was a talented student and was studying at Birmingham University for a degree in religion, theology and archaeology". As the train approached Kikar Tzahal, he reportedly stood up from his seat, pulled out a knife and stabbed a fellow passenger.
The British Embassy in Israel said it was "in touch with local authorities" but could not give any further comment.
Police there have detained a 57-year-old man, calling him an "Arab terrorist".
Russia's statement also called for both sides to avoid "unilateral moves that undermine the potential for an internationally accepted solution" and referred to "the Palestinian and Israeli people" as both having "friendly relations with Russian Federation".
JERUSALEM (AP) - Police and hospital officials say a Palestinian man has stabbed to death a British woman in Jerusalem.
Jeff Mayweather Fires Back at Dana White Over McGregor Split
Most fans might not know Jeff as much as his nephew's father Floyd senior or his other boxing uncle Roger Mayweather. McGregor now has a boxing license and Mayweather has officially come out of retirement, but only to fight McGregor.
"This is another incident of many in which a Palestinian suffering from mental health or personal issues has chosen to carry out an attack as a way out of his problems", the agency said. The attacker was apprehended by officers at the scene, police said. The 50-year-old man was injured while attempting to flee the scene.
It added: "The university condemns such acts of terror that harm innocent people, and especially a student who came to Jerusalem to study and widen her academic horizons".
President of Israel Reuven Rivlin said his country's "thoughts and prayers are with the family of the victim".
The attack took place on Good Friday, a Christian holiday commemorating the crucifixion of Jesus Christ.
Bladon was an exchange student at the Hebrew University of Jerusalem which is located in East Jerusalem on a campus with high levels of security.
Since the beginning of the unrest, Palestinians have killed 41 Israelis and two United States nationals, while Israeli forces and civilians killed at least 241 Palestinians, a Jordanian and two African asylum seekers, majority alleged attackers, according to Israel.
Israel says the bloodshed is fueled by a Palestinian campaign of incitement.