Former premier Dr Mahathir Mohamad has failed to "move on" and still viewed Singapore as an enemy, said Minister in the Prime Minister's Department Abdul Rahman Dahlan.

"He (Mahathir) has a problem with Singapore. That guy has not moved on. He still views Singapore as an adversary," Abdul Rahman told reporters in Kuala Lumpur today.

Abdul Rahman, who is minister in charge of the Economic Planning Unit, said unlike Mahathir, Prime Minister Najib Abdul Razak sought to collaborate with Singapore on the Kuala Lumpur-Singapore High-Speed Rail (HSR) project.

"I am sorry to say this but I think Mahathir is backtracking in economic development. This (HSR) is a game-changer," he said.

He was responding to a question on Mahathir's claim that Pakatan Harapan and Parti Pribumi Bersatu Malaysia would review the project if they were to form the next federal government.

Meanwhile, Abdul Rahman said questions on the declassified Central Intelligence Agency (CIA) documents on the Mahathir administration and the Bumiputera Malaysia Finance Ltd (BMF) scandal were best posed to the former premier.

"A lot have been said about the BMF scandal and people can make their own conclusions. After all the documents are there to be read.

"If at all there are questions to be asked, then it must be directed to Mahathir," he said.

The nine-page document titled 'The Bank Bumiputra Scandal: More Trouble Ahead of Malaysia's Mahathir?' was produced by CIA's directorate of intelligence and dated March 5, 1985.

The CIA believed that there was circumstantial evidence which suggest that BMF's dubious lending scheme were known to the Finance Ministry and Bank Negara at the time.

BMF suffered US$1 billion in losses as a result of the lending practices and caused major political problems for Mahathir, who was then prime minister.