In fact, he said, the living standard of the people in the two states had seen a marked change since 50 years ago, in tandem with global development.
Najib said since 2010, the government allocated RM2bil to implement 70 basic rural infrastructure projects in Sabah dan Sarawak.
He said, in 2012, a total of RM62.3mil from the RM2bil was allocated to the Sarawak Corridor of Renewable Energy (Score) for several projects, including access and internal roads in the Tanjung Manis Halal Hub, water supply in Samalaju and feasibility studies for a Science Park in Mukah.
He added, a total of RM207mil was also allocated for the Sabah Development Corridor, to implement several infrastructure and agricultural projects.
Najib said this year was very historical for all Malaysians as tomorrow the nation will be celebrating the 50th anniversary of the formation of Malaysia.
"The proclamation on the formation of Malaysia was made by Malaysia's first prime minister Tunku Abdul Rahman Putra Al-Haj on that historic day (Sept 16) in 1963 at Stadium Merdeka, Kuala Lumpur," he said.
He said it was witnessed by the Yang di-Pertuan Agong, Malay rulers, the governors of Penang, Melaka, Sarawak and Sabah and 30,000 citizens, which brought a new ray of hope for the people.
"At the time, the people, from various races and religions, dreamed of independence, freedom and prosperity in a sovereign nation," he said.
In conjunction with the 50th Malaysia Day tomorrow, Najib called on all Malaysians to work together to advance the nation's economy, defend its sovereignty and preserve harmony.
"Although still at a young age, Malaysia has built a nation that is respected, whether in the aspects of politics, economy or social.
"The sacrifices and hard work by all parties in developing the country, safeguarding the peace and prosperity all is this while will always be valued," he added. - Bernama