WASHINGTON (AP) — Native American tribal leaders are asking President Barack Obama to reject a permit for a proposed oil pipeline from Canda to refineries in Texas.

The pipeline opponents plan to make their plea when leaders of the nation's 565 American Indian tribes meet with Obama on Friday in Washington. The administration has delayed the pipeline project until 2013.

Ogalala Sioux Tribe President John Steele says his tribe fears toxic substances from the pipeline will contaminate a Missouri River water pipeline that cost the tribe $450 million and provides three reservations with potable water. He spoke at a news conference in Washington on Thursday.

Rosebud Sioux President Rodney Bordeaux says he fears damage to cultural sites. Chief Bill Erasmus of the Dene Nation in Canada also spoke in opposition.