Attorneys for environmental groups made the request Wednesday in a lawsuit before U.S. District Judge Brian Morris in Montana. They say Trump’s permit was illegal.
The 1,184-mile (1,900-kilometer) pipeline proposed by TC Energy would carry crude oil from Canada to Nebraska.
Opponents contend it would make climate change worse by increasing fossil fuel consumption.
Morris temporarily blocked construction last year, saying officials had not fully considered oil spills and other impacts. That ruling was upheld on appeal, only to have Trump issue a new permit in March.
Government attorneys say that permit is not subject to environmental laws. They want the lawsuit dismissed.