BISMARCK, N.D. (AP) — Additional environmental review of the disputed Dakota Access oil pipeline is likely to take the rest of the year to complete, U.S. officials said in court documents in which they also advocate for keeping the line operating during the study.

Developer Energy Transfer Partners also is asking U.S. District Judge James Boasberg to keep the line open, saying a shutdown would cost the Texas-based company $90 million each month.

The $3.8 billion pipeline from North Dakota to Illinois was finished after President Donald Trump pushed through its completion despite opposition and...