Both sides in the Dakota Access Pipeline (DAPL) fight dug in on Tuesday, with the pipeline company's legal maneuvering matched by vibrant displays of resistance in cities nationwide.

"What we have got to tell Mr. Trump: We are not going silently into the night. The stakes are too high for the future of this planet."

—Sen. Bernie Sanders

In the wake of the Army Corps of Engineers delaying yet again the construction of the 1,100-mile crude oil conduit, Energy Transfer Partners filed a lawsuit Tuesday asking a judge to let it circumnavigate the Corps' decision and finish the pipeline anyway. The company's CEO, Kelcy Warren—who said in the wake of Donald Trump's election last week that he was "100 percent confident" the project would be completed—denounced the delay on Tuesday as "political interference" on the part of the Obama administration.

His company, Warren said, has "waited long enough."

Standing Rock Sioux Tribal Chair Dave Archambault II called the move an act of "desperation," noting:

Dakota Access previously told the Court that if they were not delivering oil on Jan. 1, 2017, their shipper contracts would expire and the project would be in jeopardy. So they are rushing to get the pipeline in the ground hastily to meet that deadline. The only urgency here was created by their own reckless choice to build the pipeline before it had all the permits to do so. They chose to reroute this pipeline away from Bismarck and put it at our doorstep and through our treaty lands and sacred places, even after we told them that it could not pass here. They made bad decisions and are now facing the consequences. The tide is turning against this project. We thank all of our water protectors who have raised their voices against it. You are being heard.

Indeed, as Energy Transfer Partners was going to court, hundreds of rallies, marches, and acts of civil disobedience were taking place across the country and around the world, with sizeable demonstrations in San Francisco; Chicago; Washington, D.C.; Portland, Oregon; and New York City.

WATCH: The #NoDAPL crowd in San Francisco, thousands strong, shout their message in the streets. #StandWithStandingRock pic.twitter.com/5Ym1tWUMur — 350 dot org (@350) November 15, 2016

Crowd numbering in the thousands now marching to the White House! Time for @POTUS to say #NoDAPL! pic.twitter.com/NjHNHCB8Gi — Jamie Henn (@Agent350) November 15, 2016

#NoDAPL protest on the move in downtown Portland. pic.twitter.com/YXBtDy1TMN SCROLL TO CONTINUE WITH CONTENT Never Miss a Beat. Get our best delivered to your inbox.





— Mike Bivins (@itsmikebivins) November 16, 2016

Cops making mass arrests here at NYC rally in solidarity with #StandingRock! Protesters did sit-in in the street. #NoDAPL pic.twitter.com/lmdjb1vsrF — Ash J (@AshAgony) November 15, 2016

Sen. Bernie Sanders (I-Vt.)—who has been outspoken in his opposition to the project—addressed a huge crowd outside the White House Tuesday evening, demanding "sovereign rights of the Native American people be honored and respected" and declaring: "We are not going to allow a pipeline to endanger the clean water that millions of people depend upon."

Of the continued development of fossil fuel infrastructure, Sanders said: "It is totally insane and future generations will look back on us now and say, 'What in God's name were you doing?'"

He called on President Barack Obama to "stop the pipeline" while acknowledging that President-elect Donald Trump "wants this country to become more dependent on fossil fuels."

"What we have got to tell Mr. Trump," Sanders said, is: "We are not going silently into the night. The stakes are too high for the future of this planet. We're gonna be smart, we're gonna educate, we're gonna organize, we're gonna bring tens and millions of people—moms and dads and their kids—together to tell the fossil fuel industry that their short-term profits are not more important than the future of our planet."

Watch his full speech here:

And watch Democracy Now!'s coverage of the #NoDAPL day of action here: