LIMA (Reuters) - Colombian President Juan Manuel Santos said on Friday he hoped to have "civilized" talks with Nicaragua's leader to resolve a dispute over their sea border after a U.N. court slashed Bogota's maritime territory.

Both countries have warships in the resource-rich waters but Santos urged diplomacy.

"I'm from the school of having an iron fist but wearing a silk glove," he told reporters at a South American summit in Lima. "I hope to be able to tell Nicaragua's president that we will manage this in the most civilized and respectful way possible."

Santos said he plans to meet with Nicaraguan President Daniel Ortega on Saturday in Mexico, where they will attend the swearing in of Mexican President-elect Enrique Pena Nieto.

"We will explore all these paths and leave none out," Santos said. "A treaty with Nicaragua will require a conversation with Nicaragua."

Ortega has said he expects Colombia, a close ally of the United States, to recognize the court's decision.

Santos has refused to apply a ruling made last week by the Hague-based International Court of Justice that reduced a large expanse of Colombia's maritime territory, drawing the border in favor of Nicaragua while giving a cluster of disputed islands to Bogota.

In protest, Colombia withdrew from a treaty on Wednesday that bound it to the U.N. court's decision. But the action does not have retroactive impact for the waters, which have potential offshore oil and gas deposits as well as fishing potential.

If left unsolved, the dispute could exacerbate regional tensions. Left-leaning Nicaragua likely will find support with allies including Venezuela, Ecuador and Bolivia.

(Reporting By Omar Mariluz; Editing by Bill Trott)