Obama to address Tropical Storm Isaac before starting trip

WASHINGTON (AP) -- President Barack Obama will deliver an update on Tropical Storm Isaac from the White House before departing on a three-state campaign trip.

The White House is aiming to balance leadership on the storm with the president's campaign plans. Obama is scheduled to leave the White House after his remarks for a two-day trip to Iowa, Colorado and Virginia.

Republicans canceled the first day of their convention in Tampa when the storm appeared to be headed for landfall in Florida. But the party is resuming convention activities Tuesday.

The tropical storm is on the verge of becoming a hurricane as it veers toward New Orleans.