 By Nia Williams and Valerie Volcovici 
 
 CALGARY/WASHINGTON (Reuters) - TransCanada Corp sued the U.S government on Wednesday to reverse President Barack Obama's rejection of the Keystone XL pipeline, and also plans to seek $15 billion in damages from a trade tribunal. Obama, who is not named as a defendant, rejected the cross-border crude oil pipeline last November, seven years after it was first proposed, saying it would not make a meaningful long-term contribution to the U.S. economy. The Calgary-based pipeline company says the United States has never before denied a cross-border oil pipeline from Canada, and the rejection of the project designed to transport vast quantities of Canadian oil sands and some Bakken crude to Gulf Coast refineries “was arbitrary and unjustified.” 
 
 TransCanada’s announcement comes as Mr. Obama is due to host Prime Minister Justin Trudeau at a state dinner in Washington in March. The company noted that the U.S. has never before lost a NAFTA claim, however, “we have undertaken a careful evaluation of the administration’s action as it relates to NAFTA and believe there has been a clear violation of NAFTA in these circumstances.” 
 
 Toronto trade lawyer Lawrence Herman said these types of lawsuits “are all long shots,” but TransCanada appears to have a solid case in arguing that it was unfairly treated and that the decision was politically motivated.
– See you in court, eh? TransCanada, a Canadian company hit hard by President Obama's rejection of its Keystone XL pipeline project, has filed twin lawsuits seeking $15 billion in damages and a reversal of the US decision, the New York Times reports. One lawsuit, filed under the North American Free Trade Agreement, seeks damages because the permit rejection was "arbitrary and unjustified," reports Reuters. The suit claims that Obama overstepped his authority because of his "unprecedented and symbolic grounds" for turning down the project, which he argued would bring "dirtier crude oil into our country" while doing little to boost the American economy. The second lawsuit, filed in a federal court in Houston, calls for a reversal of Obama's "unconstitutional" decision and a ruling that no future president can block the pipeline project, reports Reuters. A Canadian trade lawyer tells the Globe and Mail that it's tough to predict how these kinds of lawsuits will go, but that TransCanada's argument that it was treated unfairly because the issue had become politicized appears solid. The Times notes that a win for the Canadian company would be unprecedented: In the 22 years of the NAFTA agreement, the US has won all 12 of the challenges it faced from Canadian firms, while US firms have prevailed in trade agreement cases in Canada.