ATLANTA — Holding signs and banners and chanting “Oil Kills,” protesters in Atlanta on Tuesday shouted support for Native American activists trying to stop construction of a North Dakota pipeline they say will desecrate sacred land and pollute water.

The protests against the Dakota Access pipeline have drawn international attention, sparking a renewal of Native American activism and prompting the U.S. government to block its construction on federal land, even as the company building the line expressed its commitment to the project on Tuesday.

Hundreds of people added their voices to the protest at a rally Sunday afternoon on the Bangor Waterfront.

“It’s not a victory until it’s stopped. [The administration] asked [the construction company] to voluntarily stop the pipeline, and they don’t have to if they don’t want to,” said June Sapiel, a member of the Penobscot Nation who recently returned from a two-week stay at Standing Rock and plans to return soon.

“It’s solidarity with No Dakota Access Pipeline that we’re here for and for our treaties’ rights as indigenous peoples — to keep those sacred treaty rights,” she added.

Sunday’s rally largely was organized by Penobscot Nation member Sherri Mitchell, an indigenous-rights lawyer, activist and educator and executive director of the Land Peace Foundation.

“We were all moved by the spirit to be here,” said Linda James Thomas, 59, who attended the Atlanta event in support of the Georgia State Tribe of the Cherokee.

When fully connected to existing lines, the 1,100-mile, $3.7 billion pipeline would be the first to carry crude oil from the Bakken shale directly to the U.S. Gulf.

Protests were scheduled throughout the day in Atlanta, Washington, D.C., Los Angeles and numerous other cities. Previous demonstrations have drawn celebrities including actresses Shailene Woodley and Susan Sarandon, and on Tuesday U.S. Sen. Bernie Sanders, a former Democratic presidential candidate, was slated to attend a rally in the nation’s capital.

Last week, the Obama administration, responding to the issues raised by the Standing Rock Sioux, whose land runs about a half-mile south of the pipeline’s route, said it would temporarily halt construction on federal land. Acting moments after a federal judge denied the tribe’s request for a halt to construction, the administration asked the company building it to refrain from construction on private land as well.

On Tuesday, Dallas-based Energy Transfer Partners LP , whose Dakota Access subsidiary is building the pipeline, said in a letter to employees it was committed to the project.

The letter did not address the federal request for a temporary halt of construction. But company officials said they would meet with government administrators.

“We are committed to completing construction and safely operating the Dakota Access Pipeline within the confines of the law,” Kelcy Warren, Energy Transfer Partners’ chairman and chief executive officer, said in the letter.

He dismissed as “unfounded” worries that oil would contaminate water in the Missouri and Cannon Ball rivers, and said the pipeline would address safety concerns connected with vehicle transport of oil.

“We have designed the state-of-the-art Dakota Access pipeline as a safer and more efficient method of transporting crude oil than the alternatives being used today, namely rail and truck,” he said.

In 2013, a runaway oil train in Canada crashed, killing 47 people, and in June 2016 a train carrying crude oil derailed and burst into flames in Oregon.

Demonstrators in more than 30 states planned to gather on Tuesday for what activists dubbed on social media a national “Day of Action” against the pipeline. Many used the hashtag #NoDAPL to show their opposition.

Outside the United States, activists said on social media they planned protests in countries including Britain, Spain, South Korea and New Zealand.

In North Dakota, protesters have vowed to remain until the project is halted.