"We certainly hope that due process is fully followed and that all international norms and human rights are respected," Haq said during a press briefing.
Haq avoided commenting on whether the decision to extradite Assange was right or wrong and emphasized it is not the job of the United Nations to "second guess" the decisions of the member states' judicial systems.
"It's not the practice of the United Nation to second guess judicial decisions. So we are letting the courts work their way," he said.
On Friday, Patel approved the extradition of Julian Assange to the United States on the basis that the move will not breach his fundamental human rights. Assange now has 14 days to appeal the decision and his legal team said they would do so.
The United States wants Assange on 18 criminal charges for sharing classified documents relating to national defense and Assange faces up to 175 years in prison.
The Wikileaks founder's legal team says it was in the US public interest to reveal Iraq and Afghanistan war-related files showing indiscriminate killing.