A Korean American man accused of being involved in a 2019 raid on the North Korean Embassy in Madrid appeared at a U.S. district court in Los Angeles on Tuesday for a trial on his possible extradition to Spain.

The prosecution and legal counsel for Christopher Ahn clashed on the legitimacy of the extradition, with Ahn's lawyer arguing against it, saying his client will face death and kidnapping threats from North Korea.

Cindy Warmbier, the mother of Otto Warmbier, a U.S. college student who died while in a coma in 2017 after being detained in the North for a year-and-a-half, took to the witness stand to oppose Ahn's extradition.

Ahn and six other members of anti-Pyongyang group Free Joseon are accused of breaking into the embassy, tying up the staff, and taking computers and digital files on February 22, 2019.

In a document refuting his indictment earlier this year, Ahn claimed that the raid was a botched kidnapping attempt as part of efforts to assist a North Korean diplomat and their family seek asylum.

An additional hearing is set for June 4.