Islamabad:
Pakistan's embattled President Asif Ali Zardari will remain in hospital in Dubai until further notice after suffering a minor heart attack and undergoing an operation, officials said on Wednesday.
The unpopular 56-year-old head of state flew to the United Arab Emirates on Tuesday after falling ill in the midst of a major scandal over alleged attempts by a close aide to seek US help to limit the power of Pakistan's military.
His illness sparked media reports that he is contemplating resignation, but loyalists have ruled out any question that he may step down and the president has defied many critics in already holding onto power for three years.
"He had a minor heart attack on Tuesday. He flew to Dubai where he had an angioplasty. He's in good health now," Mustafa Khokhar, adviser to the prime minister on human rights who sits in the cabinet, told AFP.
"There's no question of any resignation," he added.
Khokhar said Zardari would return to Islamabad on Thursday, but the prime minister's office later said that although the president was "stable" he would remain under observation as doctors examine the cause of his illness.
The statement made no mention of heart attack, saying only that he went to Dubai following symptoms related to a "pre-existing heart condition".
Doctors have yet to determine whether he fell ill "due to adverse reaction" to medication or "a development related to his pre-existing cardiac condition," it said after Zardari's son, Bilawal, met Prime Minister Yousuf Raza Gilani.
State media said Zardari left for Dubai on Tuesday, accompanied by his physicians and personal staff.
Zardari took office after his Pakistan People's Party (PPP) won general elections in February 2008, three months after his wife, former prime minister Benazir Bhutto was assassinated.
Although he has survived numerous crises and calls for his resignation, he has come under growing pressure over a memo allegedly written by close aide Husain Haqqani asking for American assistance in curbing the powerful military.
Haqqani was forced to resign as ambassador to Washington last month and Zardari said Sunday that he would soon address a joint session of parliament.
It was not clear if the health scare would delay that plan.
Presidential spokesman Farhatullah Babar told AFP that Zardari was in hospital for tests and a planned medical check-up, but dismissed media reports that he may be forced to step down as "speculative, imaginary and untrue".
The website of the US magazine Foreign Policy reported that Zardari had been considering his resignation over health fears and the "Memogate scandal".
The article quoted an unnamed former US government official as saying Zardari was "incoherent" when he spoke to President Barack Obama by telephone over the weekend following NATO air strikes that killed 24 Pakistani soldiers.
The row centres on a memo sent in May to the US's then Chairman of the Joint Chiefs of Staff, Admiral Mike Mullen, seeking help over fears of a military coup following the US raid that killed Osama bin Laden.
Mansoor Ijaz, a Pakistani-American businessman, accused Haqqani of crafting the memo with Zardari's support. Haqqani has denied involvement and investigators have yet to prove to what extent Zardari may have been involved.
The night raid by US Navy SEALS in a Pakistani garrison town on May 2 provoked outrage in Islamabad and humiliated the military, which was not informed of the operation beforehand.
Relations between the military and Zardari are understood to be tense. Haqqani's departure was seen as forced by the army and the political pressure on Zardari is mounting ahead of elections expected as early as next autumn.