Hollidaysburg, Pennsylvania - The man accused of gunning down a top US health insurance executive was transferred to New York on Thursday to face murder charges, two weeks after the killing unleashed a wave of public anger over the country's healthcare system.

After initially fighting the extradition, 26-year-old Luigi Mangione appeared in court in the Pennsylvania town of Hollidaysburg and agreed to be sent to New York, where the killing took place.

Among the charges facing the Ivy League graduate in New York is one count of murder in the second degree as "an act of terrorism."

Highlighting the intense media attention the case has garnered, multiple television networks covered his trip from Pennsylvania to New York live.

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Dressed in an orange prison jumpsuit and appearing calm, Mangione left the courthouse in a black SUV, escorted by several police vehicles.

After being flown by plane to an airport outside New York City, he boarded a helicopter to Manhattan, where television footage showed over a dozen officers, some in tactical gear, waiting to retrieve him.

Mangione was arrested in Altoona, Pennsylvania, on December 9, five days after UnitedHealthcare chief executive Brian Thompson was shot dead on a Manhattan street.

Mangione made two brief court appearances in Pennsylvania Thursday where he waived a preliminary hearing on firearms and forgery charges and then agreed to be sent back to New York.

Thompson's murder brought into focus widespread public anger against the US healthcare system and many social media users have since lionized Mangione.

Outside the courthouse, several protesters rallied in Mangione's defense, holding posters that read "Free Luigi" and "Health insurance practices terrorize people!"

Police say a "life-changing, life-altering" back injury may have motivated Mangione, although they added that there was "no indication" that he was ever a client of UnitedHealthcare.