CARACAS, Venezuela (AP) -- Venezuela's vice president called in the nation's top leaders Tuesday hours after ailing President Hugo Chavez apparently took a turn for the worse, and announced on national television that a U.S. Embassy attache was being expelled for meeting with military officers and planning to destabilize the country.
Foreign Minister Elias Jaua also announced the expulsion of a second U.S. official, also a U.S. Air Force attache.
Supporters of the 58-year-old president visited churches to pray for his health, a day after the government described his condition as "very delicate" after undergoing cancer surgery in December.
Vice President Nicolas Maduro told Venezuela's high military command and civilian leaders that the U.S. Embassy's Air Force attache, Col. David Delmonaco, had 24 hours to leave the country. He said the official had been spying on Venezuela's military.
U.S. Embassy spokesman Greg Adams confirmed Delmonaco's identity but had no immediate comment.
In Washington, Army Lt. Col. Todd Breasseale, a Pentagon spokesman, said, "We are aware of the allegations made by Venezuelan Vice President Maduro over state-run television in Caracas, and can confirm that our Air Attache ... is en route back to the United States."
Late Monday, Communications Minister Ernesto Villegas said Chavez was suffering from "a new, severe infection." The state news agency identified it as a respiratory infection.
Chavez has been undergoing "chemotherapy of strong impact," Villegas added without providing further details.
Chavez has neither been seen nor heard from, except for photos released in mid-February, since submitting to a fourth round of surgery in Cuba on Dec. 11 for an unspecified cancer in the pelvic area. It was first diagnosed in June 2011.
The government said Chavez returned home on Feb. 18 and has been confined to Caracas' military hospital ever since.
Villegas said Chavez was "standing by Christ and life, conscious of the difficulties he faces."
He also lashed out at "the corrupt Venezuelan right" for what he called a psychological war seeking "scenarios of violence as a pretext for foreign intervention." He called on Chavez's supporters, who include thousands of well-armed militiamen, to be "on a war footing."
Upon Chavez's death, the opposition would contest the government's candidate in a snap election that it argues should have been called after Chavez was unable to be sworn in on Jan. 10 as the constitution stipulates.
Indeed, the campaigning has already begun, although undeclared. Maduro, who Chavez has said should succeed him, has frequently commandeered all broadcast channels, Chavez-style, to tout the "revolution" and vilify the opposition.
At a small new chapel on the military hospital's grounds christened "New Hope," a few dozen supporters gathered to pray for Chavez, many weeping. But the grounds were otherwise eerily quiet, and Caracas' streets teemed with the usual snarls of traffic, street vendors and bank lines as people went about normal business.
Chavez has run Venezuela for more than 14 years as a virtual one-man show, gradually placing all state institutions under his personal control. But the former army paratroop commander, who rose to fame by launching a failed 1992 coup, never groomed a successor with his same kind of force of personality.
Chavez was last re-elected on Oct. 7, and his challenger, youthful Miranda state Gov. Henrique Capriles, is expected to again be the opposition's candidate in any new election.
One of Chavez's three daughters, Maria Gabriela, expressed thanks to well-wishers via her Twitter account. "We will prevail!" she wrote, echoing a favorite phrase of her father. "With God always."
Maduro said last week that the president had begun receiving chemotherapy around the end of January.
Doctors have said such therapy is not necessarily to beat Chavez's cancer into remission, but could have been palliative, to extend Chavez's life and ease his suffering.
Dr. Carlos Castro, scientific director of the Colombian League Against Cancer, said "it's difficult to predict" when Chavez might die, but he believes "it's a matter of days."
Castro said Chavez could face further respiratory complications if he receives more intense chemotherapy treatment.
If the president's medical team "gives him strong chemotherapy again, then it would not be surprising if some infections reappear," Castro said in a telephone interview.
While in Cuba, Chavez suffered a severe respiratory infection in late December that nearly killed him, Maduro said last week. A tracheal tube was inserted then, and government officials have said his breathing remained labored.
Libardo Rodriguez, a 60-year-old orange juice vendor, said he was very worried after Monday evening's announcement and the government should provide more information about Chavez.
"We are worried because he does not appear. The truth is that I don't know what's happening," said Rodriguez, who identified himself as a Chavez supporter.
"There are many rumors and nobody knows who to believe," he said. "We hope he's alive."
Associated Press writer Vivian Sequera in Bogota, Colombia, contributed to this report.