A public debate between Keystone XL pipeline foe Tom Steyer and the CEO of pipeline developer TransCanada Corp. isn’t in the cards.

Steyer, a billionaire former hedge fund chief, wrote an open letter Tuesday to CEO Russ Girling that alleges Keystone would cause “irrevocable” environmental harm and requests a debate at an oil sands mining site.

But TransCanada Corp., in a statement, said Steyer has other avenues to express his views and noted TransCanada has “respect” for the State Department review process.