Venezuelan President Hugo Chavez has arrived in Cuba for more cancer surgery, after speaking openly for the first time about a possible successor.
He was welcomed by his Cuban counterpart, Raul Castro, at the airport in the capital, Havana, state media report.
At the weekend, Mr Chavez named Vice-President Nicolas Maduro as his choice to replace him should anything happen.
This will be his fourth operation in 18 months.
Mr Chavez 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.
In a televised address on Saturday, the president said tests undertaken during his stay had detected more cancerous cells and that he needed surgery.
"With God's will, like on the previous occasions, we will come out of this victorious," he said.
But he acknowledged the seriousness of the situation. "There are risks, Who can deny it?" he said.
Mr Chavez said that if his health failed and a new election had to be held, his supporters should vote for Nicolas Maduro.
Mr Maduro, a former bus driver, is 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.
The president's supporters took to the streets following his announcement to pray for him.
"We're all here for him and always will be," one woman told BBC Mundo in Caracas.
"I'm so moved by the news about my president. We love Hugo Chavez, the people need him," said another.
Mr Chavez had surgery for an unspecified type of cancer in the pelvic region after his diagnosis in June 2011, and then had another bout of surgery last February along with chemotherapy and radiation treatments.
He declared himself free of cancer in May.
But speculation has been rife that the cancer had returned, prompting the opposition to call for greater transparency about the state of the president's health.
Mr Chavez, who was elected in October for a fourth time, 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 then an election must be held within 30 days.