Surgeons in Cuba have successfully operated on Venezuelan President Hugo Chavez to remove cancerous tissue, says his Vice-President Nicolas Maduro.

It was the president’s fourth cancer-related operation since June 2011.

At the weekend, Mr Chavez spoke for the first time about a possible successor, naming Mr Maduro as his preferred candidate.

In a TV address, Mr Maduro described the president’s operation as both “complex” and a “complete success”.

The Venezuelan president had returned from cancer-related treatment in Cuba on Friday.

He left again from Caracas early on Monday after being granted permission by the National Assembly to leave the country for treatment.

The illness was first detected during an initial surgery for a pelvic abscess in June 2011.

‘Delicate operation’

Ecuadorean President Rafael Correa visited Mr Chavez in Havana prior to his operation but has since returned to Ecuador.

Speaking to reporters ahead of the operation, he said the surgery was “a very delicate operation”.

“My friend and colleague, Commander Hugo Chavez, is going through the toughest times of his life,” Mr Correa was quoted as saying.

During the weekend, Mr Chavez himself had acknowledged the seriousness of the situation after tests had detected more cancerous cells in the pelvic area.

“There are risks. Who can deny it?” he said in a televised speech on Saturday.

Mr Chavez added that if his health failed and new elections had to be held, people should vote for Mr Maduro, a former bus driver and one of the president’s closest advisers.

“He is a complete revolutionary, a man of great experience despite his youth, with great dedication and capacity for work,” Mr Chavez said.

In his first speech since being named as Mr Chavez’s successor, a tearful Mr Maduro thanked the president.

“We are eternally grateful to Chavez. We will be loyal to Chavez beyond this lifetime,” he said, adding: “We are the children of Chavez”.

Mr Chavez, who was re-elected in October for a fourth term as president, is due to begin his new six-year term in office on 10 January.

The constitution states that should the president leave office in the first four years of his term, an election must be held within 30 days.