"We have seen the reports of his (a local Pakistan leader's) death while in military custody, and we would direct you to the Pakistanis for any further information on the events surrounding his death," State Department spokesperson Elizabeth Trudeau told PTI.
She was responding to a question on the death of Mutahidda Qaumi Movement (MQM) leader Aftab Ahmed, who died in the custody of Rangers paramilitary force under controversial circumstances.
MQM has accused Pakistan rangers of extrajudicial killings. According to a Dawn report, Director General (DG) Rangers Maj Gen Bilal Akber on Tuesday accepted that the MQM leader was tortured by Rangers in custody, but maintained that he died due to a heart attack.
"Even as Pakistan undertakes difficult and important counterterrorism operations on its territory, the United States remains concerned about allegations of gross violations of human rights in Pakistan," Trudeau said.
"Indeed, we consistently discuss these concerns with the government of Pakistan, in both civilian and military channels, as part of our ongoing dialogue on counterterrorism and security cooperation," she said.
"That dialogue, including at the highest levels, emphasises that any excessive or extrajudicial use of force or breaches in due process and the rule of law ultimately undermines Pakistan's democracy and long-term counterterrorism efforts," Trudeau said.
Last week in a memorandum to the State Department and US lawmakers, MQM alleged that the Pakistani Army and its paramilitary Rangers are conducting atrocities against Mujahir community in Karachi.
"Since the formation of MQM in 1984, over 20,000 of its workers and supporters (mostly ethnic Mujahirs) have been brutally murdered by the Pakistan Army and other law enforcement agencies," it said.
"Since 2013, thousands of MQM workers have been arrested and tortured by paramilitary rangers, dozens have been extrajudicially murdered and hundreds have disappeared while their whereabouts are still unknown," the memorandum said.