Venezuela's vice-president Nicolas Maduro flew to Cuba to visit the ailing Hugo Chavez and his family, while the leaders of Argentina and Peru also travelled to Havana saying they hoped to ask about the Venezuelan president's condition.

The 58-year-old president is fighting a severe respiratory infection a month after he underwent cancer surgery in Havana. Chavez has not spoken publicly or been seen since before his December 11 operation, his fourth cancer-related surgery since June 2011, for an undisclosed type of pelvic cancer.