Greenpeace activists hung their message to President Barack Obama from the Alexandra Bridge Wednesday. (CBC)

A large banner was removed from the Alexandra Bridge in Ottawa Wednesday morning after environmental activists used the structure to prop up a message to U.S. President Barack Obama.

The activists removed the banner themselves, about an hour and a half after police arrived.

Obama is scheduled to arrive in Ottawa on Thursday, but Greenpeace Canada tried to get a head start on welcoming the new U.S. president around 10 a.m. Wednesday.

That's when several Greenpeace activists hung a banner from the bridge welcoming Obama, but which also said, "Climate Leaders Don't Buy Tarsands."

"What we're here today for is to urge President Obama to say no to the tarsands," said Mike Hudema, a campaigner with Greenpeace. "[They're] one of the dirtiest and most energy-intensive sources of oil on the face of the planet."

Hudema said that Greenpeace doesn't think there's any place for Alberta's tarsands in the new green energy economy and wants to remind Obama that energy sources need to be greener on both sides of the border.

The issue remains for Obama discuss if he chooses tomorrow, but the banner is no longer there for him to see.