"No deal", Mahathir said in the interview, conducted for a business forum organised by the newspaper in Tokyo. Mahathir sacked and jailed Anwar on charges of sodomy and corruption.
"The king has accepted this, that the pardon is complete and unconditional".
"With the release of Anwar tomorrow, we will rebuild the country together".
The ruling alliance wasted no time in preparing a hero's welcome for their icon.
Anwar Ibrahim (center) arrives at a court house in Kuala Lumpur.
Differences have already appeared between supporters of Mahathir and Anwar over cabinet positions and Anwar's role.
"In fact, even from within the prison cell I sensed that the outrage against a corrupt regime was increasing by the day".
Parti Keadilan Rakyat president Datuk Seri Dr Wan Azizah Wan Ismail has been named as Deputy Prime Minister.
Anwar has spent eight of the past 20 years in prison on politically-motivated sodomy charges, and as his one-time rival, Mahathir Mohamad, secured a remarkable election victory six days ago, he was in hospital recovering from shoulder surgery.
Anwar's release on Wednesday will cap a tumultuous two decades he has endured.More news: Amazon Go Expands to Chicago and San Francisco
More news: Soros-backed foundation leaving Hungary
More news: Autopsy says single gunshot wound to head killed fallen Terre Haute officer
Without the pardon, Anwar would have been banned from politics for five years due to having a criminal record.
Anwar is thought to be "impatient to get back into office", but Mahathir won't step down until he's ready, Meredith Weiss, professor of Political Science at the University at Albany, says, adding that there's "nothing Anwar can do" to hurry along the process.
Upon his release in 2004, Anwar galvanised the "Reformasi" movement against Barisan Nasional that he started before going to jail.
Anwar, however, was again jailed for sodomy in 2015, this time under Najib's watch. Security personnel from the building - which is owned by Desmond Lim, a wealthy Malaysian businessman and supporter of Najib - were cooperative."We are looking for government documents that may have been illegally taken", said a senior police officer, who requested anonymity as he was not authorized to talk to the media.
In the 1990s, Mahathir was prime minister, Anwar who worked under him was his deputy and clear heir-apparent. "There are many faults committed by the previous government, but we can not do everything in one day, so you have to be patient".
Mahathir vowed on Monday to investigate any faults that may have been committed by Najib's government and said all ministries had been instructed not to destroy any documents.
"I'm not in a rush", Anwar was quoted as saying.
Later in his political life, he preached moderate Islam and democratisation.
Mahathir, in his remarks on Tuesday, signalled he was moving fast to effect that change.
"The road ahead will challenge the best among us to deliver what we promised to the people", he said. "We will be able to charge him".