Meanwhile US officials claime Abbas died of heart disease. That suggestion however, has done little to appease Abbas's family.
"I accuse the Americans of having killed him since he died in their custody, either they killed him directly or they neglected him," Reem Nimr (Abbas's widow) said from her family home in Beirut.
"We want to bury him in Palestine," said Nimr, wiping tears from her eyes as she sat in an armchair next to her 17-year-old son Ali, who is the youngest of Abu Abbas' three sons.
Nimr said she met early on Wednesday representatives from the International Committee of the Red Cross (ICRC).
"We had a meeting with the ICRC. The (US-led) coalition authorities (in Iraq) should hand over his body to the ICRC who will then give it to us," she said.
"But we are still in the negotiation process to know if and where we would receive him, if we would be able to take him back to Palestine. We have many questions that are still unanswered," she said.
A Pentagon spokesman said on Tuesday Abu Abbas, the Palestinian who planned the 1985 hijacking of the Achille Lauro cruise ship in which a wheelchair-bound American hostage was killed, died on Monday of "natural causes" in US custody.
Abu Abbas was taken into US
custody in Iraq in 2003
US forces on 14 April took Abbas, - after ousting Iraqi president Saddam Hussein - into custody in Iraq, where he had been living for several years.
Earlier, a representative of Abbas's Palestinian Liberation Front in Lebanon also accused the US military of causing his death by depriving him of medication.
Nazim Yusuf, PLF politburo member and representative in Lebanon, said: "they had stopped giving him medicines for 10 days at the detention center in Iraq, and he had been suffering from heart problems and blood pressure."
On Thursday the US military said that the autopsy performed on Abu Abbas confirms he died of natural causes and dismissed allegations he had been killed by occupying forces.
"The autopsy determined that Mr Abbas died of natural causes on March 8 as a result of of arterial sclerotic cardiac disease," said Brigadier General Mark Kimmitt.
"There's a lot of misinformation out there that the US assassinated him, blah blah blah, but we all know that to be patently false."