"We've seen reports that Baitullah Mehsud has been killed. We cannot confirm whether he is dead," Robert Gibbs, the White House spokesman, said.
But he added that: "There seems to be a growing consensus among credible observers that he is indeed dead."
There have been reports in the past of Mehsud's death which have proven false, but there have been increasingly confident reports that the Taliban leader was killed, along with his wife, in a US missile attack on the village of Makeen in South Waziristan on Tuesday.
The attack, reportedly carried out by unmanned drones operated by the US Central Intelligence Agency (CIA) reportedly destroyed the home of Akramud Din, Mehsud's father-in-law.
Kamal Hyder, Al Jazeera's correspondent in Islamabad, said: "We're told that there is now confirmation coming even from the political agent who would be the main administrator for the South Waziristan region - reports that he had informed the interior ministry that Meshud was indeed killed in that alleged US drone attack."
Several intelligence officials were reported as saying Mehsud had been killed in the raid and his body burried in Nargosey, a tiny settlement about 1km from the site of the reported attack.
But there has been no physical evidence of his death as Pakistani officials say it is impossible to enter the Taliban controlled area in the tribal lands of South Waziristan.
Malik said that intelligence suggested people were mourning in the area where Mehsud was tracked and targeted and that Taliban leaders were meeting somewhere in South Waziristan to decide on Mehsud's successor.
Mehsud's death would be a coup for Pakistan, which has battled his fighters since he proclaimed himself head of the Pakistani Taliban in 2007.
Mehmood Shah, a retired brigadier and former chief of security in the tribal areas, said Mehsud's death would be "quite a setback" for the Taliban.
"He is the one man who really organised the Taliban, kept unity among them and really forwarded the agenda with a lot of ... strategic thinking," Shah said.
But analysts doubt that Mehsud's death, should it prove true, will help Western troops fighting the Taliban in Afghanistan or bring an end to Taliban-related violence in Pakistan.
Karin von Hippel, a security expert at the Centre for Strategic and International Studies in Washington, said: "What happens ... is another comes in and takes their place pretty quickly."
Bryan Whitman, a Pentagon spokesman, also warned that the death of Mehsud might not have significantly harmed the Pakistani Taliban, saying that such groups can "regenerate another leader".
"I don't want to make more than one should of a single individual," he said.
The US and Pakistan have said Mehsud is linked to al-Qaeda and has been involved in dozens of suicide attacks, beheadings and assassinations, including the killing of Benazir Bhutto, the former Pakistani prime minister.
His estimated 10,000-20,000 fighters have been blamed for a wave of suicide attacks inside Pakistan and on Western forces across the border in Afghanistan.