Trump revives controversial oil pipeline projects

US President Donald Trump on Tuesday revived two pipeline projects blocked by his predecessor on environmental grounds, signaling his determination to undo Barack Obama's legacy.

Trump gave a conditional go-ahead to the Keystone XL pipeline -- which would carry oil from Canadian tar sands to US refineries on the Gulf Coast -- and an equally controversial pipeline crossing in North Dakota.

Both had been put on hold by Obama's administration.

True to his claim to be a hard-charging dealmaker, Trump said both pipeline projects would only be built subject to renegotiated terms and conditions.