The White House is threatening to veto transportation legislation that would extend money for highway construction projects through the end of September because it would mandate construction of a Canada-to-Texas oil pipeline that President Barack Obama earlier blocked.

Congress has been financing road projects through stopgap measures. This one would extend spending from July 1 to Sept. 30. But Republicans, who control the House, want to add the requirement to build the Keystone XL pipeline project.

The White House, in a statement Tuesday, said such a requirement would bypass long-standing practices on how to approve cross-border pipelines. The statement noted that a pipeline route has yet to be identified.

Copyright 2012 The Associated Press.