The grief and sadness shown by Malaysians on the day of national mourning for those who died in the MH17 air crash had succeeded in uniting the whole population regardless of race and religion, said Datuk Seri Najib Razak.

The Prime Minister said the ceremony was most significant to every strata of Malaysians who had closed ranks despite the challenges and obstacles they were facing.

"We must learn from the lesson that the tragic incident had strengthened the spirit of brotherhood, and it is up to us to look at the blessings brought by the tragedy," he said.

He disclosed this in his speech at the Prime Minister's Aidilfitri Open House at the Pekan parliamentary level at the Taman Tasik Sultan Abu Bakar, here today.

The Tengku Mahkota of Pahang, Tengku Abdullah Sultan Ahmad Shah and Tengku Puan Pahang Tengku Azizah Aminah Maimunah Iskandariah attended the event. Also present was the prime minister's wife, Datin Seri Rosmah Mansor.

Najib, who is also the Member of Parliament for Pekan, said he had focused on efforts to resolve the incidents concerning the Malaysia Airlines (MAS) flights MH17 and MH370 to ensure that they received redress without having to shout about the efforts made.

"Despite the sleepless nights and doing things which could not be publicised, I had endeavoured relentlessly to resolve the problems.

"No need to shout about it despite the success achieved, it's okay not to gloat but the outcome is more meaningful," the Prime Minister said.

In a related development, Najib said Malaysia's firmness based on the principle of truth had gained more respect for the country not only from the major powers but also the separatist groups in troubled nations to the extent that it could resolve the MH17 issue.

He said that it was also based on this principle that he succeeded in negotiating with the leader of the Ukraine separatist group, Alexander Borodai, to retrieve the remains of victims of the MH17 air crash and the black box.

"Personally, this tragedy is meaningful and close to my heart because I have negotiated with the separatist group...something that does not follow world convention.

"Alhamdulillah (praise be to Allah), these efforts were successful and we managed to retrieve the remains of the victims, and two black boxes had also been handed over to the Malaysian team.

"They (separatist group) did not want to hand them over to the other countries except to our country," Najib said.

He said that in the borderless world nowadays, Malaysia must be prepared to face whatever challenges although some of the issues had nothing to do with the country.

"For example, we carry passengers and pass through areas which are facing conflicts, although we have nothing to do with it, we can become victims," he added.