HAVANA - Venezuelan President Hugo Chavez returned to Cuba early Monday for emergency surgery after designating Vice-President Nicholas Maduro as his replacement should he become incapacitated, official sources said.

Cuban doctors had urged Chavez to undergo surgery over the weekend at the latest, after detecting a recurrence of cancer, but he apparently postponed the procedure to entrust his government to his closest aide, who also serves as Foreign Minister.

Venezuela's President Hugo Chavez takes an oath with new Defense Minister Alfredo Molero (L) as Vice-President Nicolas Maduro (C) looks on, at Miraflores Palace Caracas Dec 10, 2012. [Photo/Agencies]

Cuban President Raul Castro welcomed him Monday, and Ecuador's President Rafael Correa arrived in Havana to visit President Chavez.

"We came to embrace him in the name of the Ecuadorean Fatherland," Correa said, adding it was "a gesture of solidarity".

Chile's President Sebastian Pinera expressed his support for Chavez via Twitter, saying "due to the relapse of @chavezcandanga, I wish him much faith, strength and a speedy recovery."

Venezuela's National Assembly Sunday approved the petition of Chavez to travel to Cuba for the new surgery.

Chavez, 58, has been suffering from Pelvic cancer since 2011 and has previously received two surgeries.

In a televised appearance Saturday night, Chavez named Maduro his successor in case he is unable to fulfill his leadership responsibilities, and asked Venezuelans to vote for Maduro to succeed him as president. Venezuela's Constitution calls for elections to be convened in 30 days if the president becomes incapacitated.

"We must ensure the progress of the revolution, the victorious march of the revolution, building the new country, building the Venezuelan road to socialism, with broad participation and freedoms," Chavez said.