Perikatan Nasional (PN) has demanded an explanation from the government on what transpired during Anwar Ibrahim's recent official visit to Saudi Arabia, where the prime minister and his entourage of ministers failed to meet with the kingdom's de facto ruler, Crown Prince Mohammed bin Salman.

The opposition coalition also urged Anwar to provide a full disclosure of the cost of the trip, including the security details and others members of the entourage, to MPs in the Dewan Rakyat.

"Saudi Arabia is not only an important trading partner for Malaysia, but also has close ties with our nation.

"On top of this, the prime minister is urged to explain the failure of this visit in the Dewan Rakyat so that MPs can unravel and discuss further, in order to ensure the continuation of the close bilateral relations between the two countries," said Machang MP Wan Ahmad Fayhsal Wan Ahmad Kamal, who heads PN's international affairs committee.

Questions were raised after it was confirmed that Anwar was unable to meet Mohammed, the Saudi crown prince who is also the prime minister, despite a meeting scheduled as the highlight of his three-day visit.

Wisma Putra earlier said that the visit was at the invitation of Mohammed.

A Bernama report said the meeting did not take place as the crown prince had a change of plans ahead of the Ramadan month.

At least two diplomats who spoke to MalaysiaNow said the incident amounted to a diplomatic embarrassment for the government, and questioned the contrast in level of hospitality extended to Anwar and former prime minister Muhyiddin Yassin during his visit to the kingdom two years ago.

Wan Fayhsal said there were no news reports to indicate that Anwar, who performed the umrah in Mecca on the first day of his visit, had been given the honour to enter the kaabah as was the case with Muhyiddin and other former prime ministers during their official trips to Saudi Arabia.

He also urged the Prime Minister's Office to answer "serious questions" surrounding Malaysia-Saudi ties.

"It is common knowledge that the prime minister will only embark on an official visit when all arrangements for invitations and meetings have been confirmed by both countries.

"In this regard, did the PMO confirm all the meetings including the meeting with Crown Prince Mohammed bin Salman before leaving for Saudi Arabia?" he asked.

Wan Fayhsal also noted the importance of Saudi Arabia, not only as the custodian of Islam's two holy places of Mecca and Medina, but also a crucial trading partner for Malaysia.

"The Saudi investment through Saudi Aramco in Pengerang is one example of a high-impact investment that helps Malaysia in the development of the high-tech oil and gas industry," he said.

"In line with the firmness of the prime minister in implementing austerity policies in the administration, I call upon him to present in Parliament the entire cost of this visit, including the preparations that have been made involving all the travel costs, as well as the security details, delegations from the PMO and offices of ministers who accompanied the prime minister during the visit to Saudi Arabia."