Hundreds of people gathered outside the White House to protest President Donald Trump’s executive actions, which pave the way for the construction of two controversial oil pipelines.

“We want to make sure that the earth and the water is protected," said Andrew Hogland. “Under these acts it’s not going to happen.”

Organizers said Tuesday’s protest was last minute, planned after Trump signed directives and two presidential memoranda meant to speed up the completion of the Keystone XL and Dakota Access pipelines.

Opponents believe the pipelines will worsen climate change, and in the case of the Dakota Access pipeline, threaten the primary water supply of the Standing Rock Sioux tribe.

It was a major reversal of actions taken under the last administration.

In 2015, then-President Barack Obama rejected the Keystone Pipeline, after years of back and forth.

It was a victory for environmentalists, and in December they had another when construction on the Dakota Access Pipeline stopped. The Army Corps of Engineers, which oversees the construction of the Dakota Access pipeline, denied a construction permit, saying they need to look more closely at the pipeline's environmental impact.

The actions taken by President Trump could derail it all, which is why protesters said they felt compelled to stand outside the White House.

RELATED: Trump takes executive action on Keystone XL, Dakota Access pipelines

“I’m here because we’re regressing, and we cannot be allowed to backslide,” said Avery Raines.

"They were not joking when they said these pipelines are absolutely antiquated and they do threaten our communities of color.”

As the sun set and the temperature dropped, the group continued to wave signs, chant, and sing – but few expected Trump to reverse his stance.

Eryn Wise, of the International Indigenous Youth Council, told WUSA9 she does not “think that the legislation will change right now.”

However, she added, “It’s so important that we continue showing out. Even if it’s scary. Even if people threaten us – which they do – because, you know, if they don’t see us it’s easier for them to pretend we don’t exist and we are still here.”