WASHINGTON (AP) — Donald Trump is again setting out to unravel the legacy of Barack Obama -- this time, by signing orders to advance construction of the Keystone XL and Dakota Access oil pipelines.

Both projects had been blocked by the Obama administration.

Trump also signed a notice today requiring that the materials for the pipelines be constructed in the United States.

One environmentalist says Trump is already "proving to be the dangerous threat to our climate we feared he would be."

But congressional Republicans are welcoming the action. GOP Sen. John Cornyn of Texas says it shows that Trump "won't let radical-special interest groups stand in the way of doing what's best for American workers."

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