Mark Wilson/Getty Images A climate control activist celebrated after President Obama announced that he would reject the Keystone oil pipeline in November.

WASHINGTON -- Thought the Keystone XL pipeline was dead? Think again.

Developer TransCanada has filed two separate legal challenges trying to make the U.S. pay for its rejection of the oil pipeline and to secure a reversal of that decision.

President Barack Obama denied the permit for the pipeline, which would have run from the oil sands of Alberta, Canada, down to refineries at the Gulf of Mexico, in November, ending a tense seven-year review of the project.

On Wednesday, TransCanada said it is suing the Obama administration in Houston federal court on the grounds that the president violated his constitutional authority in denying the permit.

That lawsuit, the company said, will not seek damages. Instead, TransCanada hopes for a ruling that Obama's no to constructing the pipeline's northern leg (the southern leg has been built and operating since early 2014) is "without legal merit."

TransCanada isn't stopping there: It's also filing a notice of intent to challenge the rejection under the North American Free Trade Agreement. The company will have to wait six months from Obama's official denial before asking for arbitration under NAFTA. In that effort, TransCanada is seeking $15 billion in monetary damages for what it is calling an "arbitrary and unjustified" violation of NAFTA. U.S. taxpayers would be responsible for paying any damages awarded.

TransCanada argues that the administration's decision to deny the pipeline's permit cost it billions of dollars of investment that it made while preparing for construction. The developer also asserts that Obama made his final call for symbolic reasons that arose out of the years-long battle with environmental groups.

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