By Brian Ellsworth
BOGOTA (Reuters) - Venezuelan President Hugo Chavez will attend the Summit of the Americas in Colombia this weekend, Colombia's foreign minister said on Tuesday, in what would be a show of strength for the socialist stalwart who has been weakened by cancer.
Chavez is struggling to convince the Andean nation that he has beaten the undisclosed form of abdominal cancer following a relapse this year after he had declared himself "cancer-free."
It would also give the anti-U.S. leader, who once called former President George W. Bush "the devil" at the United Nations, a chance to openly challenge President Barack Obama in front of dozens of regional leaders.
"The information that we have is that he will attend," said Colombian Foreign Minister Maria Angela Holguin in a press conference in the coastal city of Cartagena, where the summit takes place on Saturday and Sunday.
"He almost certainly won't sleep in Cartagena. It would be nice for us if he could stay a night. Most certainly it is complicated given the treatment he is receiving."
The appearance would mark a rare foreign trip outside of Cuba, where Chavez had three cancer operations in the last year.
He is traveling back and forth between Venezuela and Cuba for radiation therapy and went to Cuba over the weekend for a third round of treatment.
Venezuela's foreign minister, Nicolas Maduro, said during a visit in Ecuador that Chavez would decide whether or not he will go. An official at Venezuela's foreign ministry said no one was immediately available to comment.
Chavez, 57, has treated his cancer as a state secret since the diagnosis last June, leaving few clues about his actual condition and raising doubts about his capacity to campaign for re-election in an October vote.
He enjoys a sizeable lead in polls over opposition candidate Henrique Capriles, who has united a historically fractured opposition after winning a primary vote in February.
Chavez's health will be the lynchpin of this year's election. In good health he can continue to spend the OPEC nation's oil revenue on pensions, subsidized food and homes for the poor. But if his health took a serious turn for the worse, that would threaten his bid to extend his 13 years in power.
(Additional reporting by Luis Jaime Acosta in Bogota, Alexandra Valencia in Quito; Editing by Andrew Cawthorne and Christopher Wilson)