CARACAS, Venezuela (AP) -- Venezuelan President Hugo Chavez is being treated for "respiratory deficiency" after complications from a severe lung infection, his government said, pointing to a deepening crisis for the ailing 58-year-old president.

Chavez hasn't spoken publicly or been seen since his Dec. 11 operation in Cuba, and the latest report from his government Thursday night increased speculation that he is unlikely to be able to be sworn in for another term as scheduled in less than a week. It was the first time the government has described the lung infection as "severe," and the strongest confirmation yet that Chavez is having serious trouble breathing after days of rumors about his condition worsening.

"Chavez has faced complications as a result of a severe respiratory infection. This infection has led to respiratory deficiency that requires Commander Chavez to remain in strict compliance with his medical treatment," Information Minister Ernesto Villegas said Thursday night, reading the statement on television.

The government's characterization raised the possibility that Chavez might be breathing with the assistance of a machine. But the government did not address that question and didn't give details of the president's treatment.

Independent medical experts consulted by The Associated Press said the government's account indicated a potentially dangerous turn in Chavez's condition, but that it's unclear whether he is attached to a ventilator.

"It appears he has a very severe pneumonia that he suffered after a respiratory failure. It is not very specific," said Dr. Alejandro Rios-Ramirez, a pulmonary specialist in Puerto Vallarta, Mexico, who is not involved in Chavez's treatment. "It does imply the gravity of his pulmonary infection that led to a respiratory failure."

Dr. Gustavo Medrano, a lung specialist at the Centro Medico hospital in Caracas, said he has seen similar cases in cancer patients who have undergone surgery, and "in general it's very bad, above all after a surgery like the one they performed on him."

"I don't know the magnitude of the infection he has, how much of his lungs have been compromised, how much other organs are being affected. That's not clear," Medrano said.

"What's most likely is that he's on mechanical ventilation," Medrano added. However, he said, while respiratory deficiency means there is an abnormally low concentration of oxygen in the blood, depending on the severity it can be treated in various ways.

Dr. Michael Pishvaian, an oncologist at Georgetown University 's Lombardi Cancer Center in Washington, agreed that such respiratory infections can run the gamut from "a mild infection requiring antibiotics and supplemental oxygen to life-threatening respiratory complications."

"It could be a very ominous sign," Pishvaian said. He said it's possible Chavez could be on "life support," but added that it's impossible to be sure without more details.

The government expressed confidence in Chavez's medical team and condemned what it called a "campaign of psychological warfare" in the international media regarding the president's condition. Officials have urged Venezuelans not to heed rumors about Chavez's condition.

The statement didn't point to any particular rumors but said "this campaign aims ultimately to destabilize the Bolivarian Republic of Venezuela ... and end the Bolivarian Revolution led by Chavez."

Venezuela's opposition has demanded that the government provide more specific information about Chavez's condition.

The Venezuelan newspaper El Nacional criticized what it called an "information vacuum" in an editorial on Friday, saying Venezuelans are in the dark because "no one speaks clearly from the government." The newspaper called the situation reminiscent of secrecy that surrounded the deaths of Josef Stalin in Russia and Mao Zedong in China.

State television repeatedly played video of a song in which rappers encourage Venezuelans to pray, saying of Chavez: "You will live and triumph." A recording of a speech by Chavez appears during the song, saying: "I will be with you always!"

Chavez has undergone four cancer-related surgeries since June 2011 for an undisclosed type of pelvic cancer. He also has undergone chemotherapy and radiation treatment.

He was re-elected in October to another six-year term, and two months later announced that the cancer had come back. Chavez said before the operation that if his illness prevented him from remaining president, Vice President Nicolas Maduro should be his party's candidate to replace him in a new election.

This week, the president's elder brother Adan and National Assembly President Diosdado Cabello joined a parade of visitors who saw Chavez in Havana, and then returned to Caracas on Thursday along with Maduro.

"In the past hours, we've been accompanying President Hugo Chavez and taking him the courage and strength of the Venezuelan people," Maduro said on television Thursday. Appearing next to Cabello visiting a government-run coffee plant in Caracas, he said they had been with Chavez together with the president's brother, his son-in-law Jorge Arreaza, Oil Minister Rafael Ramirez and Attorney General Cilia Flores.

Chavez's health crisis has raised contentious questions ahead of the swearing-in set for Thursday, including whether the inauguration could legally be postponed and what will happen if Chavez can't begin his new term. The plans of Chavez's allies remain a mystery.

The Venezuelan Constitution says the presidential oath should be taken Jan. 10 before the National Assembly, and officials have raised the possibility that Chavez might not be well enough to do that, without saying what will happen if he can't.

The constitution says that if a president or president-elect dies or is declared unable to continue in office, presidential powers should be held temporarily by the president of the National Assembly, who is now Cabello. It says a new presidential vote should be held within 30 days.

Opposition leaders have argued that Chavez, who was re-elected to a six-year term in October, seems no longer fit to continue as president and have demanded that a new election be held within 30 days if he isn't in Caracas on inauguration day.

But some of Chavez's close confidants dismiss the view that the inauguration date is a hard deadline, saying Chavez could be given more time to recover from his surgery if necessary.

Some of the brewing disagreements could begin to be aired Saturday, when the National Assembly, which is controlled by a pro-Chavez majority, convenes to select legislative leaders. That session will be held just five days before the scheduled inauguration day.

___

Associated Press writers Jorge Rueda in Caracas and Adriana Gomez Licon in Mexico City contributed to this report.

___

Ian James on Twitter: http://twitter.com/ianjamesap