Venezuelan President Hugo Chavez has died at the age of 58 after losing his long battle with cancer.
The country’s vice president, Nicolas Maduro, announced the death in a national television broadcast.
He said Mr Chavez died at 4.25pm local time “after battling a tough illness for nearly two years”.
Mr Maduro also said the army and police had been deployed “to accompany and protect our people and guarantee the peace”.
President Barack Obama reaffirmed the US’ “support for the Venezuelan people and its interest in developing a constructive relationship with the Venezuelan government”.
“As Venezuela begins a new chapter in its history, the United States remains committed to policies that promote democratic principles, the rule of law, and respect for human rights,” he added.
Mr Chavez, whose condition had been said to be deteriorating in recent days, had been undergoing cancer treatment in Cuba on and off since June 2011 – when he was first diagnosed with the illness.
The announcement came just hours after Mr Maduro announced the government had expelled two US diplomats from the country.
Mr Chavez with his daughters Rosa Virginia (R) and Maria in February
He said “we have no doubt” that Mr Chavez’s illness was induced by foul play by “the historical enemies of our homeland”.
The government announced late on Monday that Mr Chavez’s condition was “very delicate” due to a “new, severe” respiratory infection.
Mr Chavez had not been seen in public or heard since undergoing a fourth round of surgery in Cuba on December 11 in the pelvic area.
The government said he returned home on February 18, and had been confined to Caracas’ military hospital ever since.
During more than 14 years in office, Mr Chavez routinely challenged the status quo at home and internationally.
The fiery populist leader declared a socialist revolution in Venezuela, crusaded against US influence, championed a leftist revival across Latin America, and over time, gradually placed all state institutions under his personal control.
But the former army paratrooper commander, who rose to fame by launching a failed 1992 coup, never groomed a successor.
His death sets up a snap presidential election after his illness prevented him from taking the oath of office when he was re-elected last year.
The populist leader at a press conference iin Caracas in December 2006
Under the constitution, the head of Congress, Diosdado Cabello, would assume the interim presidency.
However, Mr Maduro is Mr Chavez’s self-anointed successor and has been holding the reins since the president’s health took a turn for the worse.
The man Mr Chavez defeated in October’s presidential elections, Miranda state Governor Henrique Capriles, is expected to represent the opposition in any new national polls.
He called for unity and offered his condolences to Mr Chavez’s family and supporters.
Venezuela’s defence minister pledged the military would remain loyal to the constitution in the wake of Mr Chavez’s death.
Admiral Diego Molero appeared on national television and appealed for “unity, tranquillity and understanding” among Venezuelans.
Sky’s Dominic Waghorn said Mr Chavez “used a mixture of brute force, persuasion, passion and charisma to keep himself in power”.
“Such was the adoration and devotion that mainly the poor in Venezuela felt for him that he was seen as this almost sort of religious figure, and his loss now leaves a huge void in Venezuelan politics.
“A lot of people say he is irreplaceable.”
And Associated Press reports that the self-described “subversive,” Chavez fashioned himself after the 19th Century independence leader Simon Bolivar and renamed his country the Bolivarian Republic of Venezuela.
He called himself a “humble soldier” in a battle for socialism and against U.S. hegemony. He thrived on confrontation with Washington and his political opponents at home, and used those conflicts to rally his followers.
Almost the only adversary it seemed he couldn’t beat was cancer. He died Tuesday in Caracas at 4:25 local time after his prolonged illness. He was 58.