The United States formally denied a request on Wednesday to pause the review of the proposed Keystone XL oil pipeline, a decision expected to lead to the project’s rejection by the Obama administration. TransCanada Corp’s request to the State Department for a delay was seen by many as an attempt to postpone the decision until after President Barack Obama left office and a new president more friendly to the plan took over in 2017. The White House declined to comment on the State Department’s decision.