Environmental groups are vowing to fight President-elect Donald Trump's environmental agenda from day one of his administration, while urging President Obama to gum up the works in the transition of power.

Calling themselves the "environmental resistance," the national environmental group Friends of the Earth had one of the more aggressive calls to action on Wednesday.

"President-elect Donald Trump threatens our environment and we vow to fight him every step of the way," the group said.

The group doesn't have that much problem with Trump shaking up the establishment, as they are all for that. They just don't like Trump's methods, "using fear, suspicion, racism and hate" to gin up support from "people who felt the government had left them behind," said Friends of the Earth.

The group had been a prominent supporter of Sen. Bernie Sanders' campaign for president, which Washington strategists and political advisers said had much in common with Trump's dislike of the political establishment that didn't have the people's best interests in mind.

"Like Sen. Bernie Sanders, Trump tapped into a deep resentment about the governing establishment of both the Democratic and Republican parties," the group added. "The political establishment has ignored the fight for justice and the environment. But we reject the politics of fear utilized by Trump while recognizing that we must address the fundamental issues of equality, race and class that divide this country," it said.

The Natural Resources Defense Council, probably one of the most influential environmental groups, said it is hunkering down to devise a war plan to fight Trump, which it will reveal in the coming weeks.

"Shock and disappointment," NRDC President Rhea Suh said in a letter to donors Wednesday, explaining her reaction after Trump's victory. "Like you, that's how all of us here at NRDC are feeling after witnessing last night's election results."

Suh said that shock won't "linger or, worse yet, turn to despair," as the group digs in for a fight.

"Yes, today shock will prevail," she said. "But prepare yourself, because tomorrow the battle for all the environmental values we hold dear will begin. And we must be ready."

She said in the weeks to come the group will begin sharing aspects of an "action plan" for "defending our environment during the first 100 days of Donald Trump's presidency — and beyond."

Suh also said the group will begin lobbying the Obama administration to do what it can in its remaining 70 days to head off Trump from reversing President Obama's environmental record, especially in taking action to combat climate change.

Trump has said that in his first 100 days in office, he will begin repealing a host of environmental rules established by the Obama administration. He said he will pull out of last year's Paris climate change agreement.