The Islamic State militant group has claimed responsibility, without giving evidence, for a truck attack in New York City earlier this week that killed eight people, the deadliest act of suspected terrorism to strike the city since Sept. 11, 2001.

The accused attacker Sayfullo Saipov, 29, "is one of the caliphate soldiers," the militant group said on Thursday in a weekly issue of its Al-Naba newspaper.

Saipov was charged in federal court on Wednesday with acting in support of Islamic State by plowing the truck down a popular riverside bike trail, injuring a dozen people in addition to those killed.

According to the complaint filed against him, Saipov told investigators he was inspired by watching Islamic State propaganda videos on his cellphone, felt good about what he had done, and asked for permission to display the militant group's flag in his room at Bellevue Hospital.

Saipov was taken to Bellevue after he was shot in the abdomen by a police officer at the time of his arrest.

U.S. President Donald Trump reiterated his call on Thursday for the death penalty against the Uzbek immigrant.

Trump had on Wednesday suggested sending Saipov to the Guantanamo Bay military prison in Cuba, where terrorism suspects apprehended overseas are incarcerated, but he said on Thursday doing so would be too complicated.