The U.S. Army Corps of Engineers won't yet authorize construction of the $3.8 billion, four-state Dakota Access oil pipeline on federal land in southern North Dakota, it said Monday, along with reiterating its earlier request that the pipeline company voluntarily stop work on private land in the area.

The corps' statement came in the wake of a federal appeals court ruling Sunday that allowed construction to resume on the pipeline within 20 miles of Lake Oahe. That ruling sparked a large protest Monday in North Dakota that led to the arrest of 27 people, including "Divergent" actress Shailene Woodley, who is known for her activism.

A joint statement from the Justice Department, Interior Department and the corps said it was not ready to allow pipeline work to continue on its land bordering and under Lake Oahe, a reservoir that the agency manages on the Missouri River and the water supply for the Standing Rock Sioux Tribe. It also called on pipeline owner Dallas-based Energy Transfer Partners to voluntarily stop work in the area; ETP didn't respond to a request from The Associated Press for comment Sunday or Monday.

The Standing Rock Sioux tribe believes the pipeline, which will cross through North Dakota, South Dakota, Iowa and Illinois, will destroy cultural artifacts and could pollute drinking water. The tribe had asked the appeals court to continue blocking work on the section of pipeline while it appeals a lower-court ruling from September that let work on the entire pipeline go forward.

Standing Rock Chairman Dave Archambault II said in a statement Sunday that the tribe "is not backing down from this fight."

On Monday morning, about 300 people protested at two construction sites. Woodley faces misdemeanor charges of criminal trespass and engaging in a riot, which together carry a maximum punishment of two months in jail and $3,000 in fines, according to Morton County Sheriff's Department spokesman Rob Keller. Woodley's publicist didn't immediately comment.

The federal agencies also said they're still reviewing whether there needs to be reforms in the way tribal views are considered for such projects, a process officials said they hope to conclude soon.

Officials "look forward to a serious discussion during a series of consultations, starting with a listening session in Phoenix on Tuesday, on whether there should be nationwide reform on the tribal consultation process for these types of infrastructure projects," the statement said.

Except for the section in southern North Dakota, the 1,200-mile pipeline is largely complete. Thousands of people have protested the pipeline in southern North Dakota in recent months, and nearly 125 people have been arrested since mid-August.